Thank you for all the replies. I think what was making us nervous is the doggy door he has at home. Quite a few asked what we do at home and advised we do the same thing in the RV but we can't. As I said he has a doggy door so he goes outside whenever he likes, also, our daughters are in and out throughout the day. One is in college and works part time. Her schedule is much different than ours and she is frequently home until 10:00 or 11:00 and Freddy hangs out with her. Our other daughter is an EMT and works Wednesday - Saturday 12-12 so she's home quite a bit also. When we RV its just hubby, me and Freddy with no doggy door. This is why I was asking, because our RV time is so much different than our home time.
He is a great traveller, friendly and doesn't bark. I think I'll take the suggestions of keeping times away from him to 4-6 hours, leaving the TV on to keep him company and drown out noises, letting the hosts know he's there and continue to just try to find dog friendly places and using day care for the few times we might be gone longer.
We enjoy national parks and they are not very dog friendly!