Thanks for the responses! As far as the drive goes, is it that dangerous in winter? I am planning on driving a 4WD/AWD vehicle and have some experience driving in snow.
Dangerous? No. The roads are plowed and salted - But some days you can certainly expect to find compact / slippery snow.
Here are the webcams for the route - "Function Junction" is pretty much right in Whistler -
DriveBC Lower Mainland - Hwy 99 (Sea-to-Sky Highway) Cams
4WD/AWD isn't necessary on the highway, but is sometimes helpful for getting into your accomodation. My car is a 2WD FWD minivan and does fine - But you need good Winter Tires (required by law).