Given the size of your house, if you were heating with oil you’d be burning something like 5 gallons a day. Times 30 days, times $4 per gallon.

So you’re saving $600 a month on oil, and spending $400 on electric. Sounds like you’re winning, I wouldn’t worry about it.

Or add rooftop solar. Save $400/month on electricity and pay for your rooftop installation in something like 5 years.