What do you guys think? Is up to 2 years an ok time to let this vehicle sit?
Yes. I have stored numerous vehicles through the years. I have always used a 2X dose of Stabil just as their directions say. Did you use a 1X or 2X dose? If you used a 1X dose, that covers you for a full year, and 2X lasts for 2 years.
You could still add another dose of Stabil and flush it down with a gallon of fresh gas, although that would not get the stabilized gas up into the engine unless its started and ran again.