something to consider.. A Trailer is one thing to deal with, off the bike, with wheels on it
panniers will be several things to cope with ..
Up stairs , packing into checked luggage each way, at overnight accommodations,
and many panniers don't clip together into pairs, so that is each bag..
Non BF stuff same 12" wheels & tires though, ...
I got a Carry Freedom City trailer , it consists of a suspended bag that snaps out of the frame , that you can wear,
and a frame that will fold flat within the frame's perimeter ..
Guess a regular suitcase will strap on top of the CF , biketrailershop folks tied a duffle bag on top, and used it alone on a tandem tour.. didnt say if they used indoor lodging or tent camped overnight..