Ugh. You are right, that virus just about ruins the best of all well laid plans! I agree that the Alcan is mostly boring. Northern Rockies are beautiful, but not much else along that road. The Cassiar Hwy, watch out for black bears!!! I had to brake for two, and someone else didn't brake in time... If at all possible, the Marine Highway is the BEST, if there is the option. Particularly if this is a 'once in a lifetime' trip. Hopefully, Canada will open up to travel soon. I wonder about short flight hopping down the peninsula would be cost effective? I know the flight to Glacier Bay from Juneau was relatively cheap (ferry had a change of plans for me, or would have used it)(I had reservations, they changed, then failed to notify me, but I checked in time to make flight arrangements). We 'got off at Ketchikan (2 nignts), Wrangell (5 nights), Juneau (4 nights + 2 Glacier Bay), then Haines; Back on at Valdez. British Columbia Ferry changed their schedule on me, also...
Make reservations in advance, with a VALID credit card, not a 'throw away'! I just got a room in Fayetteville, Arkansas, due to Booking.com OVERBOOKED a hotel to ten other people who did just that, I got the room because my credit card was 'good'.
Might make note, when traveling Alaska and the Alcan, particularly at night, the bison (British Columbia and Yukon), moose, and other large animals, are near/on the road!

My wife and I have made several wildlife photographic trips to Alaska and have always been amazed at the beauty and wildlife there. And we always did land based trips, way before COVID (but after we had heard about Norovirus). First, we haven't been to Chugach state park or Wrangell-St Elias. We did go to Kincaid Park in Anchorage and enjoyed it (saw a lynx and moose). We also went to Denali and not sure how you plan to spend your time there, but they don't allow private cars in. So you take a bus which may or may not stop where you want. Are you going to camp there? Or have you been able to book the one place you can stay in Denali (which is very hard to book)? If not, and you are staying outside Denali and going in by bus each day, you might not find it that satisfying. We found that Lake Clark area and Katmai and Kodiak much more enjoyable. If you can budget wise swing it, I would recommend going at least for a day to the Lake Clark area (you need to fly over). It is the most amazing experience! Other areas we really liked were the Haines and Juneau area as well as Glacier Bay National Park. I think to get to some of the areas you need to take a ferry, or at least that is how we went. Let me know if you have other specific questions. I am sure it will be an amazing trip.
PS. I post pics on flickr with the names of the places if you are interested:
https://www.flickr.com/photos/60519499@N00/albums/72157694711451270/with/30395286948/
https://www.flickr.com/photos/60519499@N00/albums/72157684829119473
https://www.flickr.com/photos/60519499@N00/albums/72157671316314736

At best, you only have about a 30% chance of seeing Denali/Mt.McKinley. It is such a huge single land mass that it tends to manufacture its own weather, and often, even though the weather is clear, the mountain will be obscured by clouds. Just how it is.

The Alaska Wildlife Conservation Center, south of Anchorage along the Seward Hwy, at Portage, is well worth seeing. You can see bears there in a natural habitat. And renting an RV is a great thing to do. If you want to go over the Denali or Hatcher Pass, an SUV might be a better choice.

Not all the bears in Anchorage are in the zoo. When my children were in a school on the edge of downtown Anchorage, recess was cancelled one day because a bear was in the schoolyard. Folks, especially on the edge of town, keep their garbage in bear-proof containers. I have lots of pictures of moose that were taken in Anchorage and, in the winter, there were times when a moose slept in my backyard. And an eagle nested down the block. Wildlife is all around everywhere in Alaska but it doesn't necessarily want to be seen.

Yes, wildlife is plentiful, and no, you don’t see all of it, but it’s there, and often, closer than you might realized. Our daughter has a cow and calf moose that go through her yard all year. Unfortunately, the cow went out on the road and was hit by a car and killed. One time she had a cow moose come up on her back porch! Bears are seen all over Anchorage, and there have even been brown bears seen walking through downtown Anchorage. You wouldn’t think a bear would go downtown in a city of over 300,000 people.