Anything in Whistler is probably going to be expensive in August, so you'll have to do some price comparisons online to find the best deal. If you don't mind a short drive to Whistler, you could also stay in Pemberton. This is one hotel in that area - https://www.pembertonvalleylodge.com/ (there are others). Of course staying in Whistler would be better as you'll have a greater selection of good restaurants, etc.
Are you planning to take the Peak-To-Peak Gondola?
On the way up to Whistler, you might enjoy taking a ride up the mountain on the Sea To Sky Gondola - https://www.seatoskygondola.com/ . There are a variety of activities available at the top, including hiking (be sure to note the warnings about "wildlife").