What is the interest rate on borrowing compared to the rate you are earning, then take into consideration the tax consequences. 

My wife and I own a couple duplexes in Florida, however with insurance costs on the rise, we're looking at Wisconsin, which is where my wife is from originally, and we're looking at small multifamily in Sheyboygan. 

My main concern is the interest rates being so high now as to whether what I'm hoping to achieve is really even possible. 

Joe its all about NPV  and rate of return for investors.. either way your going to take a pretty big hair cut out of your equity to do what your wondering about. 

What interest rate are you getting?

Even though there is low inventory, interest rates are high, and many properties don't cash flow, look harder there are always deals, you just need to find/make them.

As Vince said it is a quick guideline and won't work in most places with current interest rates and house prices. 

Just make sure you’re comfortable with the interest rate if going either route.  

I don't do this for a living and have no real world experience, but at 40% down, even with a 7% int rate, that seems like a high monthly payment.

Also I've heard of some DSCR loans that are not too far off from conventional rates.