You can try however you know in an Iowa winter there are many days that are overcast. Air source heat pumps can work on the warmer days, but you will need some type of heat that is not from PV, especially when it is below 20F for days on end. You will be better served to use the electricity for running a gas or wood furnace/boiler.
If you want to go with a ground source heat pump as an example, you can purchase from utility at a winter rate in most of Iowa and the cost is not much more than the cost of production but will require a second meter. For example, Alliant Energy runs in steps for winter rates, as more Kwh is used, the rate goes down. First step is $0.099, second step is $0.077, third step is $0.039. If you enroll in nights and weekends off peak, those rates are halved.
https://www.alliantenergy.com/waystosave/savingsprograms/timeofdaypricingiowares
Pretty hard to compete with $0.019 per Kwh. The generator has to have a minimum of capacity online and as a result, they will sell it cheap in order to recoup some of that cost. You can't build PV that cheap.
The rules are changing in Iowa quickly because there were many large PV systems installed by farmers and homeowners. The grid tie systems are getting capped. For example, a farmer installed grid tie PV to build a bank for grain drying in the fall. His rural coop has now sent him a letter stating he can only bank 2,000Kwh and the coop gets the excess for free. 2,000Kwh doesn't last long running 15 hp motors 24/7.
The biggest thing I see with grid tie in Iowa is the PV array is usually covered with snow for weeks on end. If the sun does come out, it takes several days for the snow to clear off. You will see the snow slide down until it hits the aluminum frame, then freeze there during cold spells (high pressure, sunny days, no cloud cover). So there never is a yield for most of the winter. These systems were built cheap and as a result, the PV is not seasonally adjustable.
I purposely went with an off grid system due to the rules change quickly in Iowa as the Utilities Board seems to let the utilities do what they want. The daily rate (meter charge) has seen 50 to 60% increases while the rate per Kwh has remained the same. Take for instance an elderly household of one person that uses 10Kwh per day. If the daily rate goes from $1.20 to $1.80, that makes a huge difference in the cost per Kwh. Instead of $0.18/Kwh, it becomes $0.24/Kwh.
The second reason is I can produce all the electricity I want and use it in an off grid system. I'm not limited to 80% of normal grid usage.
Resistance heater is fine for a dump load when you have excess. I would only use it for excess dump load. You actually might be better served using a air source heat pump down to about 10F as a dump load.
I would not rely on electric (resistive or air source heat pump) as major heat source for Iowa in winter.