With a 52, with in mast furling, we'd "practice." On quiet days, in Falmouth Inner harbor, we would furl the jib, and play the in mast roller furling main like a throttle. Engine idling as backup. Narrow channel, etc., etc., my interpretation of the rules is you don't have many rights in this circumstance even if under sail which we were not, so if things got out of hand, we were ready to roll up and power.
We'd get a boat length from the slip before engaging the engine and backing in under power. Based on this experience, we felt we could get to the fuel dock (a large face dock) if necessary under normal summer conditions. Our plan would be to call the marina in advance to insure the fuel dock was clear
Cannot say we ever landed the beast this way
. That would get the sweat glands goin