40lb.round of opened grana padano cheese
I think your best bet might be to re-wax the cut surface with cheese wax, available from cheesemaking suppliers, and then store in the fridge, unless you have a cheese cave handy. In general a vertical halving will reduce storage loss by minimizing the cut surface - you could have had the same cheese availability by vertically halving the wheel (with a smaller cut surface) and then horizontally slicing the half you were using, opening it like a book if looking for the "whole round of cheese" look.

Your other best bet might be a bit too late, which is to be sure wedding one has paid for the whole cheese, and wedding two is prepared to pay for a whole cheese, so that if you open it up in 3 months and have a problem, the problem is only "smaller profit" not "taking a loss on trying to store cheese for 90 days after opening." 

Linked item is just one I found as an example, not affiliated or even a customer.