I agree that it is unfortunate that most RV warranties are only for 1 year. Newmar used to have a 3 year warranty, but people took such advantage of it, they finally went back to the 1 year. I belive Entegra still has a 2 year warranty.
However it does seem to me that if you have a 1 year warranty, it does not matter when you purchase it, you will have 12 months to find warranty issues. This means that unless you skip usage for an entire year, you will always have a good camping season within the warranty period.
Ed Headington