You get 2 SP per short rest, which gives you a single 1st slot. Once you are sorcerer 3, you can get 1 SP + a single 2nd slot out of 2 short rests. You can get pretty far with a week of rest even if it isn't efficient.
Draconic 3 / tomelock 3 can twin BB (using Cha) 4 times every short rest, and has the same trick. I'm partial to draconic 3 / swashbuckler 3 for the similar reasons.
I second the barbarogue luchador.