blow breakfast all over the table
I snorted a laugh with a full mouth of cereal when I read "dinette setup. Has anyone done this before?" Most of us have.
Anyways. There are several ways to get the seats out. One method, you need two people, one inside, one out side. Unbolt with wrenches, air tools, etc. Alternatively tighten until the bolts break.
Use a grinder with a grinder disc. Wear eye protection, face protection, skin protection. Recently a member was bit pretty hard by a grinder/cutoff tool. Several gashes, I would not call them cuts. One right cross the face. Super fortunate he did not loose the use of an eye. Lesson for all us, if we are smart enough to listen.
If you have a sawsall , use a long blade with lots of little teeth, and you might be able to lay the blade along the floor and slice under the seat and cut the bolts that way....
If you know how to use one, there is always a cutting torch.