Has anybody done the back road into Whistler from Kamloops? 
Planning a week around Kamloops this summer and wondering how that road is.
 How long from Kamloops to Whistler?  Can I round trip it in one day?  Fuel availability.  Any notable stops?
Any info would be helpful.
Thankyou in advance.

You will hate it. (See pics.) 
It is one of the BEST trips you can do! I haven't done between Cache Creek and Lillooet but have done Whistler to Lillooet many times and Kamloops to Cache Creek as well. The Duffy Lake road has been repaved - completed last year. What a difference! It is slow with a lot of twisties and switchbacks. 2+ hours for the Whistler to Lillooet part. It would make for a looong day to do it round trip unless you didn't want to stop and see anything. No gas between Lillooet and Pemberton. Otherwise you are fine.
Do it! Enjoy! But wait for a nice day or you won't see squat!

I also thought it was an awesome ride. Though when I went through there it was cold, rainy and cloudy. And there was a short section of dirt road that took me by surprise. The ride down the coast into Vancouver is also very beautiful and well worth the trip.

 Just my $.02

 This is what it looked like when I went through.