Bath remodelling pros: question on drain location with larger shower pan?

I have a nice sized basement bathroom that was done on the cheap by the previous house owner. I'm building a suite in half the basement so I want to upgrade it. I ripped out a 32" square center drain fiberglass shower unit last weekend. The room is 7' square so there is room for a much bigger shower -- I was thinking of putting in at least a 34" x 48" or even a 60" long one. The problem is the drain stub ( a 2" PVC in good condition) is centered at 32" from both sides of the corner it was installed in. Larger pans seem to all have the drain in the center (half the width of whatever they may be) or close to one end, maybe 8" from the wall.

Is it possible to get larger pans that fit that old 32" centerline drain or will I have to bite the bullet and have a custom tile shower floor built in? I would like to do as much of the work myself as possible. I have gutted and remodelled two baths completely in my last house with good results but in both cases replaced a tub unit in the same location as the old one. So this is a new predicament. The old shower was mounted on a 3" high concrete pedestal. I guess I could bust it and the concrete floor below out to make room to to offset the drain to another location but would love not to have to do that.. Any suggestions?