I realize it's 4 months away, but I'm already concerned about how this situation will play out.
My husband's brother recently bought a new house, and he and his wife indicated that they would like to host Thanksgiving this year. My MIL and FIL are resistant to this idea, as they host every year and enjoy being the hub of the holiday activity. One issue, however, is that they are putting their house up for sale soon, and it is possible that they will not be able to host - even if they have a new place by then, they are planning to downsize and may not be able to accommodate a large group. I think my BIL/SIL have offered to host both because they expect my MIL/FIL to be unable to do so and because they feel like they finally live somewhere large enough to accommodate everyone.
...Except they don't. Their dining room set seats 10, although I would say it seats only 8 comfortably. At minimum there will be 11 adults and 3 children (ages 2 to 4) attending dinner. 11 adults around the table would be tight, but there isn't enough room to include a kids table in the same room. My MIL does not like the idea that some of us might need to eat dinner in a different room (across the house), but it looks like that will need to happen if BIL/SIL end up hosting.
Our house could accommodate the 11 adults and 3 children, plus my mom (who lives with us and is usually invited to MIL's, but probably wouldn't be invited to BIL's) because we have an open layout where we can fit one long table or multiple smaller tables in the same room. My husband and I are hesitant to suggest hosting, however, primarily because we don't want to step on BIL/SIL's toes. We've never offered to host before, and feel it may seem like we are being competitive with them if we offer now. In addition, we usually visit other family members and friends for several rounds of desserts after dinner with husband's family, so we would't want to be tied down with guests when we have other places to be.
BIL/SIL don't see any problems with the space and think we'll all fit just fine, but I can see this being an issue every year now going forward, and it is already bothering my MIL (who I think is having a hard time accepting the changes that come with putting the house where they raised their children up for sale). Part of me wants to just cook a small Thanksgiving dinner for my husband, 2 kids, and mom and meet up with husband's family later on, but my MIL balked at that idea when I mentioned it. However, if we are going to end up in a different room from everyone else anyways, we might as well be in a room at our own house, right? I'm trying to figure out what the best solution is that will make everyone happy, but having trouble finding an acceptable one. Anyone go through this before?