Replying to Looking for a place in Whistler for June and July

My girlfriend and I are from Quebec and we want to go to Whistler for June and July, and we're not too sure how to do our research. Is it a good idea to go down there, look out for places as we're in Whistler, and maybe stay at an hotel the first night or two as we're checking out apartments.

At first we thought we'd be better off checking online and having already a place when we get there, but my parents and a good friend of mine say it's better to get there and then check out for apartments, especially in the summer, where there's a lot of condos available.

What do you guys think? Any advice?