Another solution would be to just replace the fans with a water block kit. There’s a number of companies that make them. It means a bit of extra work and money, but would give plenty of cooling. EVGA might still have some of their own but the 1080s are oldish cards. There may also be folks who have already installed kits that have spare fans. While they probably don’t allow sale/trade posts on the EVGA forums, if you ask over there if anyone knows where you can get replacement fans for your card, someone might offer you some.
If you’re in northern hemisphere, since we’re headed into summer, a water block kit might be a good way to go depending on cash, case, etc. Fans are very important to these systems as you have now found. Folks should periodically clean fans, heat sinks, and radiators. They are great dust traps that decrease efficiency and cooling.
Good luck!