I've heard of tart pans that are closer to that size. What you could try instead would be a pan with a similar size area, if you can't find that specific pan. A 13"x7" would be 91 sq in. A 13"x9" would be another 26 sq in. A 9"x9" would be closer at 81 sq in. There may be another configuration you can find online that will be closer.
The two things you'd be concerned about when switching out the pans would be if the center of the cheesecake will get done properly, and whether the filling will be about the same thickness, again to let the filling cook through properly. Time for some tasty experimenting?