I am pretty sure Jayco will not extend on the warranty if beyond 2 years old and out the original factory period. From there like most cars there are several aftermarket companies that offer coverage. I have had Interstate on a vehicle and they covered the parts they said they would and the upside to the aftermarket plans is that it is not limited to Jayco dealers but open to a larger pot of certified shops. The shops call or you call in for a pre-approval code with an estimate for the repair and then the work is completed. You still have a deductable to pay depending on what you set.
I am not saying they are who you should use and I have not had an RV claim with them so I can't speak from experience with RV repair but on my vehicle it was done by my local mechanic without much effort. Some of the aftermarket co.s have such bad reps that many shops won't do the work unless you agree to pay and then take the claim up with your plan after the fact. You might want to check with you local RV repair guys who you see doing the work for you and see who pays and who doesn't for a more inside look at things so your not left out in the dark. He may be an approved repair shop for one or several of them.
The other weighing issue is cost vs just paying for things once it happens, if it does. Being off the lot and used they may hit you harder and mandate higher deductables not being worth the added guranteed upfront expense.
2014 375 BHFS Eagle Premier
2014 Ram 3500 Longhorn DRW CC
6.7 CTD, Aisin, 4.10's