I use lamps, because like you, my house stays around 67 in the winter, so keeping ambient temperatures at 80 is impossible without one. I use a red "party light" that I bought from wal mart. It's 25 watts and works great for my needs (cheap too). In order to keep humidity up, I put the water bowl under the lamp and I have no problems. Make sure you cover the top screen with foil or plastic or something to keep the humidity in and you'll be set.
Not impossible, my house stays at 70, and my snakes cage never drops below 80. I have a 55 gal glass. It's not impossible. However, if a light is needed, then there should be one. As long as it's watched carefully.
"Be not afraid of greatness: some are born great, some achieve greatness, and some have greatness thrust upon them." ~William Shakespeare
1.1 Normals - Apollo & Medusa
1.0 Pastel - Zeke
0.1 Pastel het OG - Dixie
0.1 Pastel het Axanthic
0.1 Spider het Axanthic
1.1 Mojave - Clyde & Bonnie
1.0 Black Pastel - Conan
0.1 Spider - Dizzy