I think I'm about as far north as you can get.  Although the temperature inside our office is pretty toasty and warm, I don't have the best circulation and my fingers get cold sometimes.  One thing that keeps my fingers from cramping up is to wear a cotton knit cardigan sweater that goes all down the length of the arms - if your arms are warm, then your fingers will probably stay warm - it works for me!!  Another thing that helps me is to run my hands under warm water faucet for a few mintues.  That warms my hands up nicely!  You could also consider purchasing a small space heater that sits on the floor directly under your desk.  This will keep your immediate work area toasty and these little space heaters are inexpensive.  

Hope you warm up soon, Jadegrniiz!!  

SNA in Alaska