Snowpack around the Whistler and Blackcomb mountain is stable at the Alpine and Treeline level. I would not recommend going lower than that as we haven`t received enough snow at lower elevation.  If we do not get snow until your arrival, I would recomment starting a little later than usual to let the snow soften-up a bit as temperature are dropping a lot at night to come back to a nice 5 degrees C during the day. 

As for the backcountry tickets from Whistler Blackcomb, you just need to pop in any Guest relations office at the base of the mountains to get them. They need to be bought the day of and you will have to show transceiver, probe, shovel, skins and cellphone.

Have fun out there and stay safe!