do you have vet
you need to be asking a vet for advise with a puppy that young
I don't care what the breed is, you just can not leave a puppy that young in a bathroom and have someone check in ever hour or so, would that person or you know what the signs are to Pravo, Caccida, Hypolycemic and Gardia just to name four and can you afford the vet bill
You say you husband will be home in 3 1/2 months in that time the puppy will be Ok to leave in a bathroom if it's health.
Please Please Please asked a vet. what to do with a puppy that young.
Good luck and be very careful.