This is going to sound like a stupid question so I will apologize ahead of time, a few years back we lived in a very small house, I run a rescue, and thou it is mostly guinea pigs, I occasionally get other animals, I kept my crates in the attic, when I did not need them, but if I had to use them for a dog, I either kept it under the kitchen table, some times in the bathtub, when the dogs I fostered where not in it, when in use I would put them in the crate in the middle of the living room floor, is there no where in the house that you could stick it while not in use.
The right size cage is one in which your pet can lie down, turn around, and have three to four inches of extra head space when sitting or standing. While the right-sized cage may seem too confining or too small to you, it is not for your dog. Please read.
proper crate sizing
I am not going against your vet, but it is hard to house break a puppy with out taking the puppy out side, and as long as I have been around animals I have never had a vet tell me this. By 12 to 15 weeks your puppy should be up to date on all of his shots followed by a yearly booster, I may be wrong, but I do not think so, please read
Vaccination Recommendations for Puppies