The Drow Coffee Lock (Warlock 1/Sorcerer 2) starts at 3rd level - feed your warlock spells into spell slots every short rest, and never sleep (only meditate) and every long rest = 4 short rests.

Note that All other races can do this at Warlock 2/Sorcerer 2 if they pick Fae patron and the UA invocation Aspect of the Moon, where you don't even need to meditate - so long rest = 8 short rests.