For weekend length dry camping you don't need either a gen or solar, just enough batteries. You say you can get more batts and be able to handle the extra pin weight. Then do that IMO.
Meanwhile you just bought a washer and dryer for the trailer so that means you intend to have shore power when you camp after you retire next year, or why buy those? So with shore power next year you don't need gen or solar either.
That's it. Get a battery bank to handle a long weekend this year, and a small inverter to run a few 120v things (TV/DVD, laptop, phone charger, whatever.) Now you still have 1000 out of your 1400 for getting things you really need for next year.