Just trying to tie all this together. You stated using a WH with two 5500 watt elements. I assume this is really only one 5500 watt element unless you had them set for simultaneous operation. And later you said 1100 watts was enough to keep the house comfortable, which is less than 4000 BTU/hr heat loss (Of course all other operating appliances produce heat which helps to heat the house in the winter). This would mean the 5500 watt unit would run only 20% of the time.
You did not say where you live. As you know, the further north you go, the less efficient a heat pump becomes. There is a lot to be said for simplicity. It is hard to beat an electric WH; and if something breaks it is easily fixed.
But the cost is the problem. Are time of use demand rates available for you?
Where I live, the “normal” rate is: meter fee, $6.75; and $0.10536/kWh. The RTOUD rate is: meter fee, $9.85; highest 15 minute on-peak reading, $5.02/kW; on-peak kWh, $0.0676/kWh; and off-peak kWh, $0.05386/kWh.
If you permit “everything” to operate together on peak, you might use 5 kWh in 15 minutes which equals a 20 kW charge and $100 in demand charges. This would off set all savings from the lower energy charges. So you have to control your demand during on-peak times.
I hold to 2.5 kW in the winter and 3.5 kW in the summer.