In that case usually it would roll to a month-to-month unless a new one is signed.

Then I worked my butt off and rolled all the cash flow from houses 1 & 2 into house 3.

Have you tested this before rolling it out?

I'm planning on putting 20% down and rolling closing costs into the loan (82k~ total financed).

I've found promising leads with SECU, and also looked into Coastal Credit Union, but I wonder if there are if there are other local portfolio lenders offering short loan seasoning periods (<6 months), or who are even potentially able to roll the rehab into the loan? 

I also have a bit of money from other investments that I am looking to roll into a second multi-family property.  

Your "quick" test underwriting isn't too far off the mark.

That is a marketing campaign I could get rolling in just 3-6 months,  targeting 4-5 counties around me, hopefully taking in 2-3 deals a month, flipping the lower level deals and keeping the best as rentals (or owner financed) to take advantage of owner finance. 

It comes time to cash-out refi and the lender wants to see rent roll numbers. 

I have not gotten plans drawn up yet as the soil test was just done.