Buster
The date in 2019 is becoming increasingly optimistic and of course it merely marks the start of the process, so it's quite likely that this will not be an issue for your when asked to move.
The Transitional Protection is intended to mean that a claimant will not receive less than they are currently receiving, so they will calculate your amount under UC and then pro rata it to the payments that you are receiving at the time from your legacy benefits, if the UC amount is more then you won't receive any TP, if it will be less then you will.
Nothing on this board constitutes legal advice - always consult a professional about specific problems