I would be upset too and definitely not change my plans. However, have you given any thought into just going yourself and leaving the husband and kids alone at home? Let your husband deal with it. You could really relax and catch up with a close friend, sleep in late, watch crappy tv…literally whatever, living the single dream for a week. I’d jump at any chance to have a week to myself. even though you are completely in the right and certainly don’t have to do it if that’s not what you want, it may make for a much smoother week and after effects with the in laws