At Camore one couple staying at the same B&B as we did, they just retired for a few months and were determined to drive thru all North American NPs in their first year of retirement (I thought it was a stupid and crazy idea).
Anyway, they did not make reservation and they were lucky that there was cancellation at our B&B so they could stay for one night - but the following night they had no place to stay - The B&B host called at least over a dozen places. After 2 hours efforts they found a vacancy (also from cancellation) at Jasper, near Patricia Lake (out of town, but very nice scenic area). Otherwise, they would have no place to go the following night.
However, once it gets to September, there are plenty of choices for lodging, and probably 30% cheaper at least as well.