Tortoise outdoors house (Meppershall SG17)

My Greek spur-thighed tortoise gets agitated when he is trapped indoors and wants to be outdoors but it’s too cold now for him. I’m struggling to find suitable outdoor house. Preferably if it can be connected to power to use heating lamp to keep him warm. He is slightly larger than the size of the palm of my hand. I would appreciate even an advice where to get it. The best l can do is to leave him free on the floor of the utility room but even though he is free to move, he gets really agitated. Thanks in advance