Can I place my puppy in the bathroom to sleep at night in winter.?

We have a maltese x foxy and he usually sleeps outside our bedroom door on his bed. We don't want him getting up and going toilet on the new lounge room mat that he seems to like (Must feel like the grass). We are thinking of placing his bedding (Which is a raised bed with a massive cushion and blankets for warmth) in the bathroom. Will he get cold in there because it's winter and it's tiled. The hallway he usually sleeps in is gyp rock and he's quite comfortable during the night on that. Serious answers please.