I would never bring in 31 chickens into our house or garage, the mess would be terrible, and our garage gets WAY TOO HOT.
Yes, I agree. My garage is too hot also - but many folks have air-conditioned garages. I don't know about the OP.
Let me explain why I would bring my chickens inside .... I live in the country and have abundant populations of racoons, coyotes, and foxes. Coons raid the chicken run very frequently. Hubby shoots 'em every chance he gets, but within a few weeks, they're back and bring their buddies. Our run is chain link fencing 8' high and enclosed along the bottom. Coyotes and foxes can't get in, but racoons scale the fence. Gate is secure. But I don't have any cover over it - 40' wide and 50' long, that's 2000 square feet that I cannot afford to enclose the top, besides figuring out even how to engineer it.
The coop is an old camper trailer on cement blocks, in the center of the run. Removed the screens and installed hardware cloth. Reinforced any points of entry. Lockable entry door and pop-door. So the birds are safe inside their coop at night while the 'coons have their party and hubby has target practice. I do move all feeders inside the coop when I lock them up at night, and check the run for any potential leftovers that would attract the varmints. It's the best I can do.
If I left for 4-5 days with the pop-door open, I would most certainly come home to all dead and missing chickens.
So.... If I HAD to leave for 4-5 days and had absolutely no one to tend to the birds, I would have no other choice. I'd clear the basement (or put all the stuff in one end and barricade it), throw wood chips on the floor, make some quick roosts, and bring 'em all inside. All 71 of them. It's a cement floor with a floor drain at one end. I could pretty easily sweep/scoop up all the mess, hose it down, and sanitize. It would be less trouble than starting over with a new flock.