Also, noone came to help them when they were hiding on the planet even though the First Order fleet was decimated, so I don’t think anyone would have sent a tanker while the fleet was still at full force.
I have no idea what the state of affairs is in the galaxy so I can’t guess what is reasonable. I guess the First Order is a powerful military entity with no particular base of operations. And it seems the Resistance is a handful of ships. And since a bunch of planets were destroyed in TFA, all the rest of the galaxy is keeping to themselves? Why couldn’t everyone run off on small ships to Canto Bight or wherever?