Not sure if you are in or out of warranty. It looks like you are still potentially covered for an other year. If you are in, you want to follow the rules, 12m or 15k regardless. You drive 1000 miles in 12 months, you change it. Failure can mean that you would lose a warranty claim. Out of warranty, do what you want. Me, I will have mine changed. I will drive 5-8k, maybe more but not 15k a year. I could go 2 years and save a couple hundred dollars, but IF the engine has an issue, it would cost MANY times the cost of an oil change. You mention leaving your rig for days, are they drilling the well to get the oil? A full service, Engine, Chassis and all should not be a whole day.
I know a number of people that have gone the Purifiner route, with additional oil capacity, regular testing and additives to replenish those that have gone. But the cost recovery for a MH is probably not there. If you time it right, you might get two seasons. they'll let you slide a little on the time, probably more on time then on miles, but probably not 3 years.