12" being the height, I assume. The whole 48" will be very spacious for one fully-grown adult. Cannot advise you on the difficulty of pulling & reinstalling an RHP though, as I don't use them. With each side being 24" x 24", it should take quite a while for the 2 of them to out-grown this shared unit.
Out of curiosity...and I know this will be down the line a while...how do you determine when a BP has outgrown its space? Corner to corner length? Behavior?