I highly recommend that they join a tour to Banff for a few days. One of the highlight of the tour will be the Columbia Ice field - they will be able to see and touch a lot of ice (not snow though) when they are up there. You should enroll for them now because tours in August are usually very full if you are late.
Blackcomb glacier is actually open since last weekend. Yes, glacier has snow all year round. However, this isn't quite worth the money if your friends are just going to see snow.