My boy loves to roam the house also, he has freedom to do as he pleases, including going out into the garden.
He has his heated house, which he warms up in. He's 4 years old, so can hold his temp well as he is quite large.
He often goes out in the garden in the evening, (dark and wet) we live in...
I have a 4 year old male sulcata, who prefers to sleep in a cooler place at night rather than his house which is kept at a constant temp.
I just let him decide. He is perfectly healthy