I have a garage about the same size as the OP. I just finished raising the roof 5'.
My initial vision was for a pony wall under existing walls but the City wanted continuous framing from slab to trusses. Couple feet and I might have done it with pony walls without permits, but was kind of hard...
It's important that it doesn't freeze for the first 7 days. Blankets are likely the most you would need in your temps.
Normally during these temps an admixture would be added to accelerate the curing and air would be added to the mix as the voids allow for expansion and contraction without...