First off there are rv campgrounds in Canmore ( 30 min before the park) and in Radium BC ( about 1 1/2 hr west of the park) that are outstanding. We have stayed at both, however we personally prefer to stay in Banff. We are a big rig and want water/sewer/power. Having set the parameters, tunnel mtn is outstanding, they have a shuttle bus that takes you in town. Our trip was a week to get there, 2 weeks mid month August in Banff, then a week home to Ontario. Parking in town is always a problem in tourist areas and not unique to Banff, we managed.edit:
We now have a 5th wheel and F250 that we can park in town, not recommending a C or A class ...