If you took the fenders off, replaced the tires with 13" or 14" would the tires clear the boat? Then have new fenders put on that would fit the tires. I have done that in the past but then I can weld and fab up what I need.
May be an option. I'm no welder, but if I can't get a swap deal, I may have to talk to some local trailer shops.
If replacing with larger wheel size, the bolt pattern of the replacement wheel must match the original wheel or new hubs will be needed. Here is how to measure the bolt pattern.
https://www.etrailer.com/faq-wheel-bolt-pattern.aspx
2000 Viper Coral 202
2013 Pro XS 200
On both of my boat trailers, there has been enough clearance that I have been able to go to the next larger wheel size without changing the fenders.