OK, you don't want to stay at the busy town campgrounds, so here goes:
Icefield can live up to it's name, snowing here on mid summers day in 2019! It's really just a paved parking lot.
Between Banff and Lake Louise there are three campgrounds on the Bow Valley Parkway but bear in mind the railway runs close to all of these, as it does at Lake Louise. There are up to 30 trains a day, some up to 3Km long taking up to 3 or 4 minutes to rumble by!
Johnston Canyon, gets very busy, maximum 27 foot.
Castle Mountain, probably the furthest from the railway but sites will not take your rig.
Protection Mountain, where the closest site to the railway is about 140M, furthest about 450M, will take your rig and probably your best bet.
Lake Louise, railway is REAL close. the nearest site is only about 60M away so very noisy and busy.
Take a look at Silverhorn Creek, it is 50km north of Lake Louise on the Icefields Parkway. It used to be an overflow CG but I believe that it has been recently upgraded. No problem with your rig and no railway here
Another option is Monarch in YOHO NP. this is an open type CG with no facilities. It is next to Kicking Horse and is used as a kind of overflow CG but it has, in the past, often opened earlier than Kicking Horse, check it out, No problems with your rig here. You can view it in street view on Google Maps.
Good luck
Trevor
