I don't think moving in with parents will work, since it isn't just me, it's me, wife, and two kids. I already have the trailer, and I don't want to have the 4 of us living out of their only spare bedroom.
I was over there again today looking at their main power panel. I think this is the way to do it. I moved a few things around and made room for a 50amp dual pole breaker. I can go through the wall, and mount a receptacle on the side of the house, and make the ~175' (just measured that) run to the trailer. Found cable on ebay, and will wire plugs on the end of it to make my custom extension cord. It looks like I'll be able to do this for under $500. I'm guessing I can re-sell the cable (taking a hit from what I paid, but something is better than nothing), and my parents could use the receptacle for a generator in the future if they want.
About the same price as just the generator, but I don't have to buy a battery charger, inverter, and a ton of gas.