What wattage should I use for my leos' 75 gallon tank to keep it warm?

[SidAndCira]

It's starting to get cold here at night time, and I want to keep the cage warm for them because it can get 50 - 60 degrees in the house. Since the 75 gallon is so tall, would a 50, 75, or 100 watt (infrared bulb) be best?

 

[acpart]

My house gets down to the lower 60's during the day and late at night in the winter. I figure, though, with the UTH, if leos are cold, they can just stay in their warm hides. Interestingly, some do choose to stay in their warm hides for winter, while others go over to the cool side and sleep for most of the winter, essentially cooling themselves. They also don't eat much during the winter.

Aliza