Great posts here on this topic!
Spjnr: thanks for the photos! I think you are right - there looks like room on the left of the spare to handle a larger tire. I saw a video that made the tolerance seem tighter, but these photos make it seem doable. Also, a "35" is usually a little less than 35 inches in diameter (varying by manufacturer).
Michael: thanks for your explanation - that makes sense. I also agree with you that a spacer might not be the best option due to shifting that considerable weight further away from the mounting plate. Physics is a bear.
Stu_Barnes: regarding visibility - I drove a Wrangler JKU for quite some time on 35's - you get used to the reduced visibility out the back. But just because you get used to it, doesn't change the fact that you do have reduced visibility, and that is not ideal. In my JKU I also had a wiper motor blocking visibility out the back, so there was basically nothing to see when looking in the rear view. I find if you only use the skinny pedal on the right, and not that bothersome pedal in the middle, you don't have to worry about what's behind you ?
35s won't be the choice of most international over-landers, due to the difficulty in finding tires. In that regard, the stock tires will be best for finding spares and for range (fuel mileage). But most of the guys I know here in Colorado will want to lift the vehicle and put on 35s. We have a lot of rocky trails here and the added ground clearance brings a lot of peace of mind, and opens up trails that would otherwise be too difficult. Plus, in America, bigger is always better ?