If you have time, just give it three or four days in the fridge. That's the "best" way to thaw anything, I believe. But leaving it in the sink overnight would be fine, too. I do that frequently if I'm pinched for time.

Pulled off smoker at 9. Found out the element in the oven is burned out, so back on the smoker til it hit 203° at 1 am. Put in small cooler to rest this morning. Had a couple slices of flat for breakfast. Not a moist as I like, but it is tender. So much for a shorter cook, it was 14 hours total.