4 room tent is going to be stupid huge, heavy, and hard to set up even being an instant tent. I think the closest you are going to find at a reasonable price is going to be something like the Ozark Trail 20x10 Dark Rest Instant Cabin Tent. Mind you, I personally dislike Ozark Trail tents, but this does suit your requirement... Why one giant tent instead of 2 smaller ones? The issue with the Ozark Trail tents is that OT does not rate them for use in any conditions beyond a perfect gentle summer afternoon in your backyard.
Now that is reportedly the "official stance" of Ozark Trail. HOWEVER, I have heard good things from actual owners / users of Ozark Trail tents.
FWIW, my all time favorite tent has been my Coleman Sundome 6 10x12 from 2005, sadly I loaned it to a friend to take his kids to scout camp and have yet to get it back, 2 years later...