Movers

I know that this will sound like a silly question, but... We have a 6 year old caravan which still suits us well..we don't envisage changing it for a number of years yet. We take it away for 5 weeks to France in the summer year increasingly we wish we had a mover.  My question is - are they portable? If we were to get one fitted and we did change the van in a few years, could it be removed and refitted to the new one? Thanks in advance