I am having a hard time imagining why a four player game is out of the question with 1 deck. What are the reasons behind the restrictions?
Has anyone actually given it a try, and if so, how did it go?
You can have 4 works in one wing and 4 works in another wing without triggering end of game, 5 (or more)cards in hand, that's 0.5 cards fir assistants, workbench and sales.
On the otjher extre if you have any assistants and materials or sales there is not enough cards for works - no fun.
Any way game will probably and with deck exhaustion before it begins to be fun...