I think I could handle 40 (maybe more) acres by myself (more or less, I'd need help occasionally) because if I had that much I'd raise cattle (and possibly other large stock, but definitely cattle) and a few horses to ride to check said cattle. So like 1/2-1 acre for the house and surrounding permaculture beds, 2 or so for fruit trees and shrubs and a large annual garden, then the rest would just be pasture and hay ground. Why don't I list chickens? I'd probably have a coop near the house for breeding and raising chicks, and just because I love having chickens around the yard, but if I had that much property and the resources to buy/build all the necessary infrastructure, I would do intensive rotational grazing and follow the cattle with chickens, which would be housed in large mobile houses. And obviously I would need a LGD to guard the chickens... See, I have it all planned out! The only thing missing is the money to fund said idea...
Not to be a pain-in-the-butt know-it-all, but moles are insectavores. It's a common misconception that moles eat roots, bulbs, and root crops, but it's not true. They may nibble a veggie here or there, but never enough to do much damage. It was more likely pocket gophers, which are really common here in MN. I tell you this not to be a know-it-all (well, that might be part of it) but because it may help you control them if you know what is actually stealing your crop!