This reminded me of the scene in Jaws where the guy sees the shark and tells the captain "You're gonna need a bigger boat."
In other words, if you want to print that large, you need to plan ahead. That means a bigger enlarger and a brighter source than a medium format enlarger will give you. You are also probably going to have to wall mount the enlarger or build a drop table like Matt suggested. If you have the space, you are much better off getting an enlarger that was designed to do big prints, like a Durst floor standing one. I forget the models.
You can get the ventilation adapter for your 1c and put a 250 watt bulb in it, then turn the column around and project the image on the floor. I'd put a glass carrier in there though otherwise you will never get a sharp print. Replace the lens too. That could get you to 40" with a bright enough light so you don't have to wait all day. It will still be a long exposure, but won't be too bad.
Hope that helps give you an idea of what you will need.