Drive both? Volt is a sportier but smaller and less roomy car. Clarity is a great family car. In bitter cold you might as well drive on gas anyway as your EV efficiency will be very poor. When I say bitter cold I mean highs in the single digits F or colder. So like 3 weeks to 1 month a year for me in Iowa, probably more in MN. Drive both with the batteries dead. The cars drive very differently that way then with a charged battery, especially around town.