I'm like you in that I cannot afford to lock up with a hot forge inside. I pull the fire apart like others have suggested and if it is not dead cold ( test with hand above coals) before I flip the main electrical disconnect switch to the whole workshop, I scoop up the embers into a steel bucket and leave it outside.
Before final exit from shop I do this check 1.Fire cold 2.Gas to 2nd forge off 3. Gas to all other bottles, 3 of them - oxy, acetylene, argon- off 4.mains elect off.
best wishes
Steve