Not impossible but yes amazingly daunting task to take on. FF6 came in 94, and the graphics and amazing things they had it were the beyond the scope of anything at the time. World changing events, epics graphics, soooo many locales, airship, ghost train fights....the list is super long. To bring all that to the standard of the FF7 remake!, yeah it would take forever I'm sure.

I wouldn't be opposed to a remake on a lesser scope get the graphics but.make them a little my update not quite human appearance of course. Touch up graphics, maybe add verbal dialogue, input cool cuts scenes with cgi and put maybe some extra scenes here and there or extra screen time for lesser characters. There are ways they could potentially do a remake but more a updated version rather.