Would you be better off selling and purchasing a less expensive property that would require less carry should it become vacant for some period of time?

Yep, been doing it full time since 2018ish.

The only reason we don't qualify for traditional lending is because I took some time off to help my terminally ill father, and my husband has been in a commission-based role for less than a year (the lender said you need 2 years of history for that).

All things considered, on the market for months, its now winter time, cold weather, holidays, and dark at 5 pm, not prime selling time, I offered $250,000. 

Next time just give 90 days notice.

This happens all the time, usually with heirs, but it can be squatters as well.

But in my experience, you would be better off spending that same amount of time/hustle working a second part-time job with guaranteed income, then investing in buy-and-hold properties. 

He can spend the next few years-ish getting a finance degree through an online school while working part time, but he just got offered a full time position helping with sales for a local wholesale real estate company. 

A very simple platform that saves time, keeps leads organized and makes it easy to lease up.

That moratorium is supposed to be temporary.Mind you, while the US used to have (some of the) lowest interest rates in the world for the last 15 years, this is no longer the case and the US actually has some of the highest interest rates in the world nowadays and that doesn't look to change any time soon.