Perhaps Oogway could sleep anywhere. I mean, turtles sleep inside of their shells, so Oogway could basically recoil into his natural protection and take a nap anywhere he wanted. Makes sense, no?
@Firecat19 Considering that we are talking about a fictional world where a bug is strong enough to flip and toss a panda dozens of times his size, I think a turtle surviving in the winter would not be that far-fetched.