Hi all, I purchased a 2004 Prius about 6 months ago. I come from a Jeep Wrangler background so the Prius was a bit of a culture shock. My question is...During the summer months we averaged 42-45 MPG, now it's winter in NY with temps. I get that mileage is worse in cold temps due to battery being cold. I drive 2.5 miles to work (5 miles both ways) When I checked consumption for the last 150 miles I'm averaging 19 mpg. The ICE doesnt stop running and I'm barely up to operating temp in the short ride. Should I let the Prius get up to full operating temperature before leaving? Thanks.