For winter work, I use an REI Arete - It's 5 pounds, but does a great job in wind and cold. I haven't had any heavy snow on it yet. For the rest of the year, I use an old Tarp tent Squall, 2 lb, and does a good job.
Cooking is the only issue with these tents, I got a Golite Shangri La 3 for that. It has it's drawbacks but you sure can cook in it!
Merino wool is one thing I can't say enough good about. I swear by my base layers. I do like to sleep in different base layers than I wore all day long. It's heavier, but if I don't sleep good, why am I out there anyway (IMO)? I also carry a silk sleeping bag liner (3.8oz) That has saved my bacon a couple of times. I do sleep cold.
Have a good trip cross country, I think you'll love living in the Rockies!