My father just went into the long term care facility on December 23rd so the circumstances regarding the use of his house have definitely changed.

While the property's location was desirable, it was evident that the house had been neglected for several years.

If they’re late a third time, you have a strong case for eviction for habitual non-payment—without risking the tenant showing up at the 11th hour with the money.For your specific circumstances, with only a partial month behind, I would guess there is a decent chance they can come even on rent and it would be a waste of your time.

However, weighing your options and performing due diligence carefully based on your specific circumstances, the property's potential, and your long-term goals.

Do you have any suggestions on how we can secure long-term financing under these circumstances?

I have wanted to flip since the early 2000's but never could due to extenuating circumstances.

If you opened the exchange with the intent to hold the property for investment, and then in the future circumstance changed which caused you to reconsider the use of the replacement property and convert it to personal use, then a period of time less than two years might be reasonable.  

One of the biggest issues is probably borrower default—whether due to mismanagement, market downturns, or unforeseen circumstances, lenders can end up in long, costly recovery processes.

My question is that due to numerous unfortunate circumstances, two properties that my partner and I purchased (through a program) were underscoped, and we cannot move forward financially.

However, this is not specific legal advice to you, just an opinion based on the circumstances described.