I like your thinking because bigger is ALWAYS better. I've always read and gone by the standard of 4sqft/bird inside the coop, 10sqft/bird outside in the run, 1sqft of ventilation per bird.
Even with this standard it will hold 29 chickens, so OP is 4 birds too many. Not great but not horrifying. If things can be adjusted to get through the winter there are things can be done come spring to make things really right. I'm so glad we got those dimensions! Thank you
@SilkieSisters !
Ok, in the picture your solid walls on 2 sides look about 4 feet high, yes? The left hand wall looks like it could be an outside wall to your house or a shed perhaps? The unseen wall you have described as solid wire. I'd love to see it. Is it also covered in plastic? Does it have a door?
Assuming my image of your coop walls is correct, or close, here's some ideas.
Cover the lower wire area (circled with green) with plywood or something that will not allow wind through. Remove the plastic only from the upper wire area above it. If you can do the same on the unseen wall all the better.
Considering you have a couple extra birds you want as much floor walkabout space as possible. The tubs catching poop is not a terrible idea, really. But it takes up floor space. A thin flat board hung about 8 inches below the roosts will catch the poop. I saw someone a sheet of cloth to catch poop. Not perfect but hey, we're improvising here! The idea is to clear the floor of "furniture". Floors are for walking on.
What is the item on the left side looks like a bookcase? Is that nest area? Hang milk crates or make a from that wall about 18 inches high for nests. Opening the floor up will reduce stress in the flock.
Lastly but possibly most important after ventilation is moving the food and water outside. I already mentioned why.
Here's one you won't like but trust me and a whole bunch of us northerners (New Jersey here, ice storm central). Remove any heat. It doesn't allow the birds to acclimate as nature intended. It causes condensation, is a fire hazard, and if your power goes out in a storm they aren't acclimated so they freeze to death.
All of this is just suggestions to help you come up with some winter solutions with whatever you have on hand. Use your imagination and fix these issues if only for winter. And keep us updated so we can help with snags along the way.
Good luck!