My thought is I buy a multi-fam (off market preferably) and house hack for 2 years then move south.

That said, I know a few MHP operators that make some pretty tremendous money on the trailers, mostly by renting to people who need to pay in cash and have someone not ask a lot of questions - illegal/undocumented immigrants, transients, probably some criminals for sure, sometimes people (mostly women) hiding from domestic abusers, etc.

It works the exact same way and it's the same exact lease with one difference - they specify that they are renting a bedroom and not the whole house. 

I have a house, I plan to sell this spring.

The specific location ( 4' * 6' long) is underneath a guest bedroom window in the front of the house. 

(They have the deferred maintenance you'd expect after a fixed income senior lived in them for several years, plus smokers, pets)So how do I turn 5 straggling houses into a proper real estate portfolio and well-managed rental business? 

Currently listed 2 houses 1.5m each and the market is dead.

I would learn all you can, go to meetups, build relationships, but only buy something now if you are going to house hack it for the two years until you go and then just rent out your unit when you go.

Purchase price: $295,000 Cash invested: $22,000 Before moving into this house we had to add piers under the hours as the previous were not grounded with cement.

People do not sell houses or properties like they are a commodity.