We are tearing out old tub and tile surround.

We are tearing out old tub and tile surround. Expanding the end walls each a foot, installing a bench at one end. Interior dimensions about 53 inches by 36.

I'd redo the walls in tar paper on concrete backer board. Add the schulter corner beads just like they do for tile. And glue the laminate down like they do on countertops. For the bench edge I could again go with a shlulter bead. All on top of a mud pan because I want the drain location at the same end it was before instead of moving it to the middle.

But since my size is wider that the 48 inches I think laminate comes in what do I do for that last 5 inches? I've seen one or two examples of one level being laid down horizontally with another layer overlapping on top but that doesn't look nice