It might be an oversized load, but most bathrooms can. Fancy master bathrooms would not fit though.
There is more than that though, as the floor needs to be designed for where the pipes and wires of the prefab bathroom come out. Not impossible, but not easy either. A lot of modern houses are adjusted on sight for where the pipes have to be as the architect doesn't check if a pipe and beam are designed to go in the same place.. (in large building the architect will check, but not in something small.)
There is more than that though, as the floor needs to be designed for where the pipes and wires of the prefab bathroom come out. Not impossible, but not easy either. A lot of modern houses are adjusted on sight for where the pipes have to be as the architect doesn't check if a pipe and beam are designed to go in the same place.. (in large building the architect will check, but not in something small.)