I used a buddy heater last year, and had the same issue with dampness, ice on the insides of the windows, etc.
Fireball, I know you said no electricity, but this year I'm going to try a small genny, a 50' extension cord, and a ceramic heater, or maybe a oil filled portable radiator, or both. I don't mind cold, but I hate damp.
PS: +1 on the CO detector.
