3 yrs on our first 4x4. Used it once but that was because I did something stupid...because...I had 4x4. Only got it because it was about the same price as the 4x2 but in better condition.
If you don't go off roaing or need it now, you won't need it with the trailer. Indiana isn't horrible snow belt area. We have had 2wd trucks in Michigan for decades and the only times we've been stuck, 4wd wouldn't have helped.
For the trailer you mention, a 1/2 ton should be fine. A 3/4 ton would be nice if you plan to move up to a bigger trailer (or even a srw 1 ton).