We are thinking of adding more in the future depending on the relocation plans.Buying a new property in Seattle will mean a new mortgage for 30 years and very likely incur a high DTI with high monthly payments.

Several have mentioned utilizing low down payment second home loans for qualifying.

Look how many died in the Great Recession which was nothing as severe.On the other hand, the debt-free ones will be in a much stronger and better position to survive (because they have no debt payments to make).  

Unlike the Bay Area, at least from my experience in Sacramento, i don't think the difference in down-payment from a duplex and tri-plex is that significant.

As others have suggested, you could get a conventional or FHA loan if you want lower down payment options.

Until the house goes through the foreclosure process, I am making monthly interest payments.

As long as the rents can cover both the current PITI and proposed P&I payment, credit is at least 680. you should be able to qualify. 

I still remember the first loan payment coming due and wondering where that money was going to come from!

I have a W-2 Job, capital saved up for a down payment (or two), and a buy box based on my affordability.

my condolences on your recent lost.there are a few ways you can do this, as mentioned above you can take a heloc on your primary residence which will give you a second mortgage, first mortgage payment wont be impacted. you can do cash out refinance which will give you one mortgage and payment. it will pay the old mortgage and give you money in your pocket to pay for the rehab.or you can do a renovation refinance which is similar to cash out refinance but we would contractor involved  as part of the refinancing and they are paid through the loan