The only problem you might encounter is that once upstairs, it may be tricky to get them back downstairs should you need to. This happened with my old cocker who when she went to stay with my parents when we were away, created merry hell when she had to sleep downstairs. For this reason, despite loving her sleeping on our bed, our new puppy (5 months) is still downstairs in her crate and will stay there for the foreseeable future, although is allowed up for a cuddle at weekends. We are very lucky though in that she is the first dog I have know who will sleep in, I woke her up at 9am this morning!