The cold night probably didn't kill them, but it's likely that it slowed them down. If the temperature is not fairly steady throughout the fermentation period, you will probably need to make corrections - like you attempted (or the opposite if things are warmer/progressing faster than expected).
The key to corrections is being proactive. Adjust the temperature as early as possible. It's usually too late to do anything in the last few hours, and you might actually make your situation worse. Start watching the balls at least 8-10+ hours ahead. With more time, you can make smaller corrections, and more importantly, it gives you plenty of time to get the dough back down to the temp you want to work it. Making pizza with hot dough sucks.