Visiting in laws and pull out couch or bed?

ok my in laws were going to come visit me and my husband in nc last month and my mil said no b/c they needed money to go on their cruise in a few weeks and since we said we can't make it for thanksgiving or x-mas due to my husbands schooling and the army we invited them to come in nov. all of a sudden her view changed and she said she'd do anything and it was up to my fil to work it out. she doesn't work and always complains about money and uses that as an excuse to not visit and expects up to drop our live to come visit them in la 900 miles away. if they do come which i hope not we recently bought a couch with a pull out queen bed and will put a futon mattress on it but i know it won't be good enough for her and she'll once again sleep in our room in our bed. is there a nice way to tell her that they will be sleeping in the living room this time and that we would like our bed and room this time?! also i set my a/c at 66 b/c i am very hot natured and like to be comfortable