There are no better or worst places to stay - there are just places. You'll discover that CG's are open 8-10 weeks per YEAR so they are not top class. And you won't care because you are there for the far north adventure not some CG with various facilities. Here's a big clue:
In Yukon with a population of 36,000 and 186,272 square miles you can meet one person every 5 square miles – how’s that for a big front yard?
About staying at the next CG: Leave by at least 9am and stop by 2pm - you'll be ahead of the rest of the pack. You can't do anything about the caravan reservations but you can be ahead of the rest of the pack and have a better site or just get in. And if not just pull off into one of the various possibilities and there are many.
OK a class A is more limited than a hummer but still lots of options. I'd certainly advise towing but lots of options...
Sure a 9,000 mile trip to a foreign county is daunting but - yes Canada is a foreign country but very friendly.
A caravan camper let us copy his itinerary and we went to most of their tourist places. If you scan our
Alaskan Trip blog you'll pick up most of them.