You're tackling the problem from the wrong end, Toola. I'd be more interested in finding out wht it causes the fuse to blow in the first place.
Even if you had a small consumer unit outside the bathroom, it would still need to be protected by a fuse or breaker at the source......... defeating the object of easy access for re-setting.
With a heavier cable up from the main board, it could be done, but with certain provisos.
Perhaps you have an 8 or 9 kilowatt shower? That might cause the fuse to blow. That's the first thing we need to know.