Part of these funds has already been ear marked for renovating our house to create an Airbnb unit, which will help the financial freedom goal, but that's not the focus of this question...

We comepletely renovated one unit and moved into that one unit.

Added, how do you assess the property as far as how much you might need to invest to renovate/fix?

The wording in some of the references I was going by seems to say that you can't write off HELOC interest unless it was used to renovate, or improve the home against which it is secured. https://www.irs.gov/newsroom/interest-on-home-equity-loans-often-still-deductible-under-new-law

I am so tempted to buy the fixer upper and rehab it but I've heard and seen some horror stories of people who have done renovation loans where their property has been sitting around for months with the work undone.

Larger homes that sell or rent for more will be required to make the deal pencil.The exception is in places where you can put a humber of tiny homes on a lot.

Unfortunately when a home is renovated for a flip it is generally a poor choice as a rental.

Getting a mortgage in my personal name is not an option.I’m preapproved for larger amounts.

In the past year, we started a renovation to add the second bathroom but ran out of funds (this is an attic conversion and our contractor was way low in his estimate).

Make sure your agent communicates the reasoning why your offer is low (extensive renovations are needed, place is old, layout needs work, building permits needed, etc.).