I asked the CL manager and I looked on the internet, and there doesn't seem to be a carriage ride from WL anymore, only FW. But, that doesn't mean that couldn't change. Rooftop viewing was only a limited, special occasion event so there was never a guarantee that it would be offered. In fact, when we had it scheduled last year, there was lightning in the area so it was canceled at the last minute. It's easy getting over to FW, is there a reason why you wouldn't want to do the carriage ride from there? It's an easy walk, bus or boat ride to FW.
Besides a cake, CA Grill, strawberries (or other in room dining celebration), Wishes cruise, carriage ride... I can't think of other ideas in the WL area. You could take one of the boats right before Wishes. They usually will stop in the lake so guests can watch and it's free.