watch your pipes.
do you have forced air or baseboard water? if you have water, you need to cycle it in the basement at least. There's some tools that hook on to thermostats to do this for you.
ThermGuard
I have a level of my house below pellet level which keeps the furnace running and calling for oil and plus my regular hot water boiler usage. It's enough to keep the basement pretty warm (60s) so I don't have pipe issues.
If your basement is getting cold, you're going to want something to keep it over 55. Especially this weekend.
It might be wise to just run the furnace flat out (crank it to 80 to ensure it runs) for a few min before you go to bed.
I like it 68-ish in my living spaces and 64-65 in my sleeping area. any hotter than that and I sweat.