People with no space where are we putting our litterboxes?

Okay so I used to have 3 cats, but one died and i was so distraught that my mom immediately got me 2 new kittens from a family friend who will be living in my room for a couple months until theyre big enough to play with the dogs. (They still spend time around the house/visit other houses and get to play all day, i promise they are very cared for and i do everything to provide anything i can for them.)

however.. we now have 4 cats instead of 3, and while it worked when Oppa and the rest were the only cats, to have 2 litterboxes, (Peanut and Baby use the one downstairs, Oppa and Baby use the one in my room) im starting to think its going to be a problem!! We do have 4 litterboxes but only 2 in use because we have not that much space.. Yes i understand 3 cats two litterboxes also wasnt ideal but Peanut was actually supposed to be the only cat in the house lmao😭.

So for any advice on where to put the 2 litterboxes, i will js name the rooms we have n which ones may be able to fit it n which oenes wont/cant.

We have 2 bathrooms, one upstairs that literally couldnt even fit one large dog.. so no space whatsoever. The other one is my grandpas and he’s disabled so i wouldnt enjoy making his bathroom harder to navigate.

We have 3 bedrooms, a litterbox is already in my room, and theres no space for any more because i have 2 water fountains, a cat tower, a cat scratcher, and my own personal things as well as cat toys. My mom/brother share a room and the only place i could imagine a litterbox is a mini closet that we covered because its cluttered, and we didnt want my little brother exploring it. 3rd bedroom is my grandpas so no.

Lving room, Basement, Kitchen, Dining Room, Closets: We already have a litterbox in the living room (bottom of the stairs), and no more space to put any more because the rest of yhe room is filled with my brothers toys. Dining room is kinda nasty to put a litterbox but yk.. it doesnt have space either because we store our dog food and mop in the dining room. Kitchen no go thats js gross, Basement I absolutely would love to put the litterbox in the basement… however i wouldnt be sure where or if its possible. Our washer and dryer r in the basement, as well as a makeshift “bedroom” for my grandma on one side of the basement, on the other side is our car and one of our dogs is too shy to go outside and uses the bathroom in the basement (we throw out her droppings ofc), and theres also my brothers baby carpet, so while i do think its the best place im just very unsure. I just dont want them not to have enough options with how many cats we have.