Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

You have 2 issues that can be solved by one piece of hardware. With only 15 gb of storage left, your laptop's drive is too full. The general guideline is to leave at least 25% of a drive's capacity in free space. When programs execute they open temporary files on the drives, programs will use that drive for scratch space and in general a drive that has a lot of reads//writes/deletes on it will be slow (if it is a mechanical drive) as it seeks open sectors to store data.

So, while your primary motivating force may be to provide additional storage for your trip, which can be solved by a variety of methods, the bigger issue is you are out of room.

Getting an external drive is how Apple wants it's users to handle this. Depending on which model you have, it will either have Thunderbolt 2 or 3 as an external drive interface. There is a significant advantage in speed between a fast mechanical drive and an SSD, but the cost of a 2 TB Thunderbolt 3 SSD will range around $700, while a fast 4 TB G-Drive with Thunderbolt 3 will cost only $320.

You are going to need something - a USB memory stick, external drive, SSD external drive - or a bag full of SD cards. My suggestion is a compromise - get a fast mechanical drive with 2-4 TB storage, but stay away from the cheap junk that sells for around $100 or less. A G-Drive is an OK but slightly pricey solution. I prefer purchasing an enterprise/datacenter quality drive and putting it into a hard drive enclosure. Hitachi, now owned by Western Digital, offers a 4 TB drive for $153 on Amazon, https://www.amazon.com/HGST-0B35950-20PK-4000GB-7200RPM-26-1MM/dp/B07D3YH466/ref=sr_1_3?dchild=1&keywords=4tb+ultrastar&qid=1602151817&s=electronics&sr=1-3 and you can get G-Tech Thunderbolt enclosure for another $30 to $50 depending on interface, with USB 3 being the slowest and USB 3.2 Gen 2 being the fastest. I like this one - https://eshop.macsales.com/item/OWC/ME3NH7T00/?utm_source=google&utm_medium=shoppingengine&utm_campaign=googlebase

For under $200 your problems can be solved with a drive that has a proven track record and a 5 yr warranty.

Blair Shaw Jr Loc: Dunnellon,Florida

jerryc41 Loc: Catskill Mts of NY

Move what you won't need on your trip onto an external drive.

Look for duplicate files that you can delete.

An undesirable alternative, as far as I'm concerned, is to use a program to compress some files on your computer. I never liked compressing files, but some people still do that.

You can bring a small portable drive, but that means carrying more gear.

Maybe what you want to hear is this: Do some research and buy yourself a new laptop.

Picture Taker Loc: Michigan Thumb

Get a small 1 to 3 TB external hard drive.

repleo Loc: Boston

Clean up your hard drive. Sort through your files and delete the junk and archive anything you don’t need. Start with files that haven’t been modified in the last year. If you haven’t opened it in 12 months you probably won’t open it in the next 12 years.

47greyfox Loc: on the edge of the Colorado front range

I had a similar dilemma last January while on a workshop in Costa Rica. Luckily we were still in San Jose, so I went to a local discount store and picked up a 1TB SSD.

frankraney Loc: Clovis, Ca.

You have two problems. One is your hard drive is full. Should have at least 25% empty. So I would follow Gene's and others recommendations and get a good external drive at least twice as big as your internal . I would then either move or delete any unnecessary files from your internal drive to the external . This will not give you a backup so be carefull which ones you move. Secondly I would do as others have said and buy plenty of cards for the camera and then once they're transferred to the external drive keep the cards as a backup. Then when you get home I would buy a new laptop with a larger hard drive, and another external for a backup of the first.

As an afterthought, it sounds like you have no backup of your hard drive, so, first things first, buy two external hard drives ( at least twice the internal) and take one and make an immediate backup of your internal drive.

Toment Loc: FL, IL

I’m not sure how many terabytes you need but I use my iPad and a dongle to unload the cards each night. Have fun.

photoman43

The first thing you need to do is free up space on your laptop,s hard drive. Remove as much as you can onto an external hard drive. Your computer needs that free space to operate properly. My rule of thumb is to always have at least 20% free.

Then buy an external SSD or spinning drive or both for your new images. I always triple backup my images with cards, ex drives, etc. get the largest size SSD that you can afford. 1 tb minimum. For a spinning drive, 2tb or 4 tb.

a6k Loc: Detroit & Sanibel

You have many good suggestions above. I just want to offer some help for when you ask about computer issues.

Computer "memory" is usually RAM and is much different than "storage". Your issue is with storage. Most or all of the replies you received saw through this issue but you will get better results in future with correct terminology.

When you add external "drives" you are adding storage.

frankraney Loc: Clovis, Ca.

The op did say storage, not memory.

DirtFarmer Loc: Escaped from the NYC area, back to MA

If the trip is imminent, you should get more memory cards AND an external hard drive (spinner or ssd) for your laptop. On the trip, download the memory cards to the computer but do not reformat or erase them. Take the files on the computer and dump them onto the external hard drive. That way you have at least two copies of your images: one on the cards and one on the external disks. There's another copy on your laptop but you should treat that as transient so you don't impact the rest of the laptop data.

If the trip is a while off, or when you get back from it (so you have some time to work carefully) clean off your hard drive. Better to do this when you have time to do it rather than try to dump things in a hurry and risk mistakes.

You should be putting things you don't use frequently on an external drive so you have it available but it isn't loading up your laptop drive. And of course, things you don't expect to use at all you can delete. (I prefer to back them up on external drives rather than make decisions about future needs, which may change with time).

And get into the habit of keeping your laptop drive clean and backing things up.

markngolf Loc: Bridgewater, NJ

Upon returning, you might consider replacing the Mac hard drive with one with a larger capacity. It's easy and usually not very expensive. You don't need a new laptop if you are satisfied with the current one's performance.
Mark

DirtFarmer Loc: Escaped from the NYC area, back to MA

Also:

Time Machine

Longshadow Loc: Audubon, PA, United States

But the title is "Computer Memory"......

(I agree with a6k by the way.)