You probably cannot accomplish your goal. However, when we went to Southern Africa there was a weight limit, take less clothing to offset the "excess" camera weight. Use a camera backpack to get your gear there and do not plan on bringing the pack into the safari vehicle.

However, most importantly, during the trip occasionally put down the camera and enjoy the animals, people and landscape.

I use an on the go plug that reads SD cards and has USB ports with my Samsung phone and tablet. I backup my SD card each day to 2 flash drives. I have done this for years without any problems. I would not travel without being able to have at least two copies of my images. I have also used a Kingston Mobilite and 1 tb hard drive within my backup scheme. It is slower but works just as well. Neither system requires a laptop.

I am not in favor of using one SD card each day because you have no backup if the card is either lost or damaged.
I would rather have two copies and not need the second then need the second and not have it. I have had quality SD cards fail during a trip.

I used the Canon G-3x and for the most part was very happy with it. The exception being BIF and continuous shooting in RAW. Prior to that camera I shot with Canon DSL and SLR for about 50 years. Two years ago I switched to the Olympus EM-1 Mark II. For travel I take two of three lenses. Always the 14-150 and, if there is wildlife the 75-300. For cities I replace the 75-300 with the 9-18. I use the 14-150 probably 85%+ of the time. It is a light setup and I can enlarge the shots up to 20 x 30. As much as I liked the one lens for all, two for all is much better. The EM-1 series has some great features that aren't available elsewhere.

Topaz does not charge for each update. When I purchased DeNoise AI the first year's updates were free after that there is a modest annual to receive updates for all of the Topaz products I use (DeNoise, Sharpen and Gigapixel). I doubt that any software company provides free lifetime updates.

When I started using LR & PS I watched (and continue to watch) Matt Kloskowski, Anthiny Morganti, Piximperfect, Phlern and Photoshop Cafe. Each has strengths and weaknesses as far as their teaching methods. Watch some and find whose methods work for you and check out others periodically as you learn more about the programs.
As others have said you can stop and watch it again. I also have "created' my own knowledge book that I can refer to without searching out a YouTube that I watched a year ago.

Since this is a trip with your grandson and not a photo expedition, go light and small. I have been to Yellowstone in the fall and winter. Do not take the 135 mm. Think enjoy the moment more than photography. When we were in Yellowstone in the fall less than 4% of my keepers were taken with anything longer than you 150 mm. Travel light and you will have a better time. With the Olympus you should not even need a tripod.

My wife and I are both photographers and as such we have taken photography specific trips as well as non-photographic trips and tours. We have found that we turn all trips into photo trips. We always have our cameras with us. If on a non-photographic trip we are careful not to hold up a group but we still take a reasonable amount of time (especially early in the morning) to shoot with purpose.

If you are selling all of your current gear, why limit yourself to only Canon? For me, if small and light, but not pocketable was the issue I would get the Olympus OMD EM10 Mark IV and the 14-150 mm lens. Better image quality than the SX740.

Make sure that your camera and equipment is insured and go use it. Your daughter is correct. The Leica might be the "holy grail" to you but it is a brick sitting in a drawer or closet at home while you use a smart phone camera.

Unless your camera has two card slots using multiple cards does not provide a backup of the pictures.

No, I use SD cards because my Oly EM1 M2 has two SD slots.

Once you travel super light you will never go back. We have travelled for u to four weeks with a carry on and backpack for each of us. The bottom half of the backpack carries our individual camera gear, chargers, batteries and other miscellaneous stuff. When we went to Scotland in 2019 we each took our Oly em1m2 with the 14-150 and I brought the 9-18 as well and had extra room in our baggage and backpacks.

Now the 24" x 20" is truly a full frame, 36 mm x 24 mm is just a tiny cropped sensor!

One other thought. When you are travelling keep the backups in separate places. That way if something is stolen or lost you do not lose all of your pictures. I have found that I try to have three backups, one in camera and one or two on flash drives and I carry one of the flash drives with me when walking around and on transportation. I do not want to even think about having spent the time and effort to back up everything and have it all lost because the camera and the backups were all together.

Also, I carry a number of SD cards and only clean/format a card when I have run out of cards. I see no reason to travel with a very limited number of cards. I have had cards fail and even have the lock fall out. When that happens the camera considers the card locked and will not write to it. Cards are cheap and small, bring spares. I always carry one spare SD card with me, it and the flash drive reside in a small plastic bag along with a sparer battery in my front pocket.

Yes, I am a belts and suspenders guy when it comes to travel photography.

I have used various back up systems while travelling including using micro SD cards, flash drives and hard drives. Depending upon how long the trip is and how many pictures I expect to take drives the system. When using the HHD I use a Kingston Mobilite. It creates a wifi connection to my phone or tablet to control the process and has two ports an SD slot and a USB slot. It tends to be slow. When I use flash drives I connect at multi port card reader to my phone or tablet. The card reader has an SD slot and two USB slots. This setup is faster. Additionally, my camera has two SD card slots and I have them set up to save each shot to both cards. In my second card slot is a microSD card with adapter, by pulling out this card I can put the micro SD card into my tablet and review my shots and/or do some minor processing. We travel light so we never bring a laptop.