I wouldn't worry about calculating return, per se.

A dwelling needn't be occupied per se to be claimed as a homestead, however, you would need to prove with undeniable certainty that there has been a total abandonment with an intention not to return.

Your family income and family frugality is another HUGE advantage, especially when combined with the previous point about housing costs in SE WI.  

There are plenty of worthwhile investments at the 1% level, and in my opinion, even at the .8-.9%.Is the home located in SE Raleigh?

I did not have it "set up" per se, but I did form a relationship with a lender and had a pretty strong indication that I would be able to refi after rehabbing my cash purchase.I actually found 2 lenders, both small and local.

I'm looking in Eckington, Brookland, Capitol Hill, Lincoln Park, Anacostia and other parts of SE DC.

The address is 12030 SE Rhone st.

If you want the 401k contribution, you'll be paying SE tax. 

Welcome Ryan, I too am in SE Michigan!

Depending on the market you are in, those amounts can buy/rehab anywhere from 1 property (CA for example) to 12 properties (SE MI for example).