Unless you're going to put a lift and a set of off-road tires on any Tahoe, I wouldn't consider it a stock "true off-road" vehicle. The approach angle at the front of a stock Tahoe is too narrow and it has too long of a wheel base. Plus it's too wide for most mountainous trails. So you won't be able to take a stock Tahoe on such technical trails that 17" or 20" wheels would matter. However, you are correct with the general statement that more tire is better when off-roading then you can adjust tire pressure as needed.

 

Go big or go home.....