Thank you all so much for your responses! I feel so much better now.
I think I'll just hold on to my reservation and see what happens. I am still hoping we can get adjoining rooms at FFI, but if we have to stay apart, that's fine too. Maybe I will talk to my MIL and SIL and make sure that is OK by them. I was able to hold my original ressie at Del Sol and can cancel with no penalty, so that is always an option, too. I WILL NOT stay in a room with four adults and a toddler, that is just too much!
I'm not too worried about being able to meet up each day, but I am worried about the jealousy factor. So maybe not inviting them back to our room is a good idea. We didn't really have hotel activities planned, other than swimming, hanging out, etc. The sad part is that my MIL is the sun worshiper who loves laying out, which is why I thought we should move to FFI in the first place, as the Del Sol's pool is practically non-existent! Oh well! More park time, right!
Thanks again all for listening. You know you can always count on your fellow DISers to understand the weirdos who don't want to plan every detail of their trip