After summer I turn down the heat, or rent them furnished for month-to-month winter rental (bonus money) and go visit my daughters or take my boys snowboarding.  

If she leaves, then all her belongings will leave with her and you can do the heat treatment which is done in one day (but is MUCH more expensive). 

Heat is brutal through at least early October so that leaves about 2 to 3 months.

The house is in very good condition, other than it has no central heat and air and some countertops and laminate in the kitchen.

With all the markets heating up it's getting more difficult to achieve some of these but we still use it as a guideline to help us evaluate pros and cons of properties.1)Cap rate above 10%. 2) no rents less than $700. 3) 3br only.

I'd like to include it in my leases and head off an issue that is likely to come to a boil when the presidential election heats up.

Utilities not onInoperable heat supplyMissing or insufficient weather-strippingLoose or torn carpetMissing or cracked electrical outlet cover platesCracked or peeling paint on wallsCracked or broken window panesMissing refrigerator kick platesEvidence of roof leaks/pipe leaksDirty stoves, ovens or walls and unkempt perimeter surrounding houseInsufficient bath ventilation and inoperable smoke detectorsLeaking faucets or plumbingNo temperature/pressure relief on water heatersYou screen your own tenants, then you submit the paperwork to have a tenant approved by the Housing Authority.  

My tenant just texted me saying that the glass cracked on the stove in one of my properties from when she was cooking on medium to high heat.

The Lease needs to be clear in its definition of what you are trying to accomplish here which is that the Tenant pays for all of the operating and maintenance expenses of the property.In addition be sure to include an understanding of who pays for major capital replacements (not just maintenance) such as replacement of the heating and air-conditioning units, water and sewer lines, electrical mains, roofs, glass, etc.

I think central heat/air could go out of style if ductless heat pumps become cheaper and easier to install or if window/portable heat pumps become cheaper, more compact/sleek, or more efficient.