If you do an analysis of the weld, you will find that the 110V mig does not get full penetration on the 1/4 in material. And on 3/8" it will appear to be only surface deep. Yes you can make it hold, maybe. But structurally, the welds are not what a 220V 200 amp unit will make. Flux core does have a little more penetration, and is one reason it is so popular on these small units. Of course, I am talking single pass weld, which you'd typically have in a farm scenario. You can weld up to 1 inch or greater with a 110V mig if you have the patience of Job. But it may not be practical.
I grew up in the grading and clearing business. One day a guy questioned my dad why he charged so much money for clearing oak trees. He said he knew of a guy that would do it for half my dad's hourly price. My dad knew the guy he was talking about, and he had something like a 350 John Deere, and my Dad had a larger 1150 Case. My dad's response: You can hire someone to dig these trees up with a spoon if you want... Point made. The guy hired my dad.AND... My point is that 110V's have their place, but a 220V larger mig can accomplish things a lot faster and more efficiently.