You may be "borrowing trouble" at this point. Unless there is the scent of another male dog, or the lingering perfume of a female in "heat," you very well may not even have a problem.
That said, I'd make very sure to clean all the carpets really well, then use an odor neutralizer generously after they are dry. I'd also do a thorough wipe down of the walls, from chest-high down, with some type of odor neutralizing cleaner. I'm going to assume that you are taking your furniture with you and he is accustomed to it, which will help him a lot in acclimating.
Really, though, most dogs don't care where they live, as long as they live with their beloved owners. Just make sure he has his old dish and some things that make him feel at "home." He'll probably be so thrilled at being inside with you that nothing else will matter. Rotties are intelligent creatures; don't worry too much ahead of time. Moving is enough of a worry without fretting over something that more than likely won't happen. Good luck!