As mentioned above, I would go with a 6x7 or 6x6 enlarger on a cart (microwave, cabinet with casters, etc). You "might" be able to put a 4x5 on a similar cart, all depends on the size of the baseboard and the cart. With the cart, you can roll the cart out of the way and into a closet or the corner of a room. This is what a friend of mine is doing; stored in the corner of the family room (under a cover) then rolled into the bathroom to print.
The problems with diassembling any enlarger between sessions are 1) how to disassemble/assemble, 2) what do you put it into.
1) I disassembled a D5 with color head when I bought it. It took TWO of us to safely separate the column (with attached head) from the baseboard. And I would think it would again take TWO people to reattach the column to the baseboard. The column with the attached head is heavy and clumsy to handle. Smaller enlargers (6x7 and smaller) are MUCH easier to break down, if you have to, less bulk and weight to handle.
2) The box for my Omega 6x7 is pretty BIG and clumsy to handle. I can barely handle the box myself, without a cart to move it. I would hate to have to deal with packing a 4x5 enlarger away and moving the box(es). And the space that the box(es) take up will be similar to or more than the space that the enlarger will take up.
Having said this, I use a Durst M600 (6x6 format), and I have to store it broken down in its box between sessions. Luckily it assembles and disassembles quite easily. The box for the Durst M600 is less half the size of the box for my Omega 6x7 enlarger. I guess the Europeans have a similar space problem and have to pack things away between sessions. I print in a small half bath, where I can't even roll a cart into the half bath. The enlarger sits on the closed toilet, though I am thinking of getting/making a small table to fit over the toilet, to raise the enlarger higher. In my old apartment, the enlarger sat on a piece of 1/2 plywood over the bath tub.