Yes you can always do a dinner for just the 4 of you. You should do a search of the things to do in the small town you are going to. It has a college with dormatories so it is bigger than the town I grew up in. Any bed and breakfast there. Google the town and find out. Anyway, I still like the idea of doing something special with your SO before and/or after. If you are going to be totally uncomfortable with the ex and her family then you should see if you could do the nice quiet breakfast or lunch with your daughter and her fiance'. I'd bring my laptop to the dormatory if I was the SO and do my own thing. I am sure you SO understand that your ex is being controlling and this whole situation is because of your love for you daughter. Even I get it
Don't beat yourself up for this one weekend of what is supposed to be very important to your daughter.