Two days ago I texted her the amount that she would need to pay September 1 is XX dollars and she balked, telling me she didn't know what prorating was and had expected to pay each months full rent on the 16th of each month, which she had "always done before". 

The new landlord told me she would share feedback with the tenant if it is negative.

He told me she has it for sell but is giving up on it by the end of this month.

This way, if the tenant/roommate was doing nothing legally wrong but we just didn't mesh well, we were not contractually obligated to continue sharing our own home with this person.Overall, we had a great experience renting out rooms and it split our mortgage in half.

I had asked her why all of a sudden this was an issue for her and she told me she was entitled to her land and she had “plans” for it and I understand she’s entitled to her land but I have no idea what her “plans” could be it’s such a small spot just big enough for there mailboxes and borders the 2 properties and she’s trying to sell the place so why does she care?

If you have a smart thermostat that also goes offline, then it isn't the lock but the WiFi router.

Most modems have multiple Ethernet jacks and I just run a separate router off that.

She offered to introduce me to the representative from the city, who assured me she was approved for the program and was in great standing.

I live out of state and my realtor has been managing the property for me. She

Then I would get some quotes and start budgeting now ... depending on what the municipality charges for connection, the length of the new run and the digging/landscaping involved in disconnecting the old, you could be looking at 3 - 10K.In the interim, be nice to your neighbour and perhaps higher a roto-router service once - or twice - per year to hit the existing line and keep it clear.