We were there two weeks ago and it was the highlight of a two-month trip. We stayed at the big park hookup campgrounds, Banff Trailer Court and Jasper Whistlers. They were full, but I'd keep checking online as people do cancel.
If/when you go to Lake Louise, go very early in the morning. The lakes are stunning but parking lots fill early. There are many, many Asian visitors in cars and tour buses. Same was true at Peyto Lake on the Parkway - parking lot so full we couldn't get in. Came back when we drove southbound early on a Sunday and got lucky.
If you go up to Jasper, book the Whistler Mountain tram ahead. We didn't, thinking we'd wait for good weather. Waited in line on a Saturday for a half hour and then learned there would be a further 1.5 hour wait.
We had clouds and rain off and on, but sun out often. We had two chances (going up and back down) to get nice photos. It's a spectacular area.
