In the winter of 2015, I wanted to purchase another home.

We want to escape the winters at home but don't want another home to finance/maintain.  

Under state law, they have no obligation to notify you of their sabbatical and provided they pay the rent and make reasonable accommodations to secure the unit, keep the heat on in the Winter, etc you can't and should not do anything.Since your tenant has not paid rent you have a valid reason to file for a UD, however, you will have an issue with giving them notice and I do not know what the proper method is, so you should consult an attorney since if you do not give proper notice your eviction case will be thrown out of court.  

If holdover tenant remains then you could be rehabbing and selling in the heart of winter ( not recommended ).Sounds like the owner has big health problems and does not have the mental energy to get them out.

Wait till you have more liquidity and are able to invest 50k into a deal without breaking a sweat.I agree with @Heidi Pliam that you should get more familiar with both debt and equity deals and the pros and cons of both.Take a deep dive and read/listen to actual books on apartments, syndication, and creative finance.NOTE: The next economic winter is approaching.

Weather doesn't hurt either considering how long and cold winters are up here. 

I don't do carpet 99% of the time,doesn't last. here the tile is very popular as we have warm winter in Texas.

.…………………………..I was in the backyard of my primary residence this past March, raking up all the leaves I had left to rot over the winter, in attempts to get the property ready to sell.

Have been cleaned and used every winter but they are 38 year old masonry chimneys with wood stoves connected.

Last Winter my HOA used salt that cause damage to my leadwalk.