one combine we left with duals, but it as the combine that got stuck, and also you just didn't try to go anywhere questionable. 

We put some great big fat tires on the other combine...

had them on for about a day, weren't much better, then got a set of tracks..

the combine also had rear wheel assist.

I wont say that it can go though "anything" but if its wet enough to get that thing stuck, you probably shouldn't be out in the field, no tractors/wagons or semi's would be able to be in the field that's for sure. 

I'm with someone else who said fill the grain tank on those, put some weight on em.

I don't see this test as really showing a whole lot.