One thing beneficial .. off the bike you have 5 or so things to deal with,
4 panniers + perhaps, a handlebar bag.. + the stuff on therearrack,
Vs 1 bag on its own wheels..

In the case of a carry-freedom,city trailer, and Brompton's folding bike
the trailer can carry the bike .. then itself fold flat..

my 20" wheel Burly flatbed, pop off 2 QR wheels, unsnap the truck-tarp
fabric over the short side rails, so they come out, and it folds pretty flat too.

Using front panniers on Front Low Rider Racks, And a Trailer
resolves Heel strike/ rear Panniers on short Chainstay Road Bikes Go away..

And the front load makes the steering stable..

or Ala Brompton touring bag, 1 big Frame Mounted Bag in Front.
or maybe a Porteur Rack, Bag..


and have a trailer for the other stuff..