Totally get this, the whole "cold room for sleep" thing feels like such a blanket rule. A bit of warmth just helps your muscles unclench, you know? My old apartment had terrible heat and I slept terribly until I got a good space heater. What's your perfect sleeping temperature, then?
Cold rooms are the only way I can sleep without waking up sweating. Science says your body temp needs to drop to kick off sleep, and a cool room helps that happen. Getting too warm actually messes with your sleep cycles. Maybe it's because I run hot, but bundling up in blankets in a cold room gives me the best of both worlds.