@Stephen Foote
I would not wait. I would but your multifamily unit now with the VA loan and just move in. Ideally your tenants should be able to cover the mortgage payments. In my opinion you should still be able to live a frugal life that mirrors that of living with your in laws because you'd run the numbers and the property should cash flow. You would still get to keep your reserves, live frugally, have tenants pay down mortgage, and become a real estate investor. Unless you just want to stay at your In laws or somebody else wants you to stay there because it's nice. I honestly don't know what there is to solve here besides you wanting to say something is your primary residence when it's not.
Debt is too cheap now, and rates will more than likely go up. If you wait to save your way to a down payment you could be chasing interest rates as they climb.... in my opinion only reason not to buy you Multifamily house now is because you can't find a good deal or you think real estate will be cheaper in the next year or so because of a" crash ".
I believe you have nothing to lose by buying and living in your multifamily property for little to no money down and if it cash flows will help you drastically beef up your reserves. Do it. If you're not ready though there is nothing wrong with that. That's my 2 cents. Thank you.