i think lots of folks have different reasons for wanting to keep their canines inside at night. for me, i have big dogs, although they have adequate kennel space, i think it helps them to be able to stretch out at night and warm the stiff muscles in a comfortable room on a carpeted floor.
they (2) also normally empty a big bowl of water over night as well, thus ensuring they are fully hydrated to their needs and rarin' to go the next day, and the next day, and the next day.....i usually put them on the ground for 4 or 5 days consecutively, so yeah, i take pretty damn good care of them at night, because i ask a lot of them the next day!...just the way we do things.