2014 Gas Range

I recently purchased a 2014 Volt. The battery seems to work fine however I don't think I have seen its full potential being that here in KC, MO we are in the dead of winter. When fully charged it estimates 31 miles. I am hoping that estimation it higher with warmer weather however the battery could have degraded some too. A bigger concern I have is the gas range. When researching I always saw 38 miles for battery and ~345 miles for gas with premium fuel. Unfortunately even with premium fuel my estimated gas range is 200-215 miles. That is a serious loss of miles. I was expecting a range comparable to my previous traditional ICE Hyundai Sonata but I am losing about 100 miles. Has anyone else experienced this? Could something be wrong? Does the ICE lose range in the winter too? Does the range estimation provided not factor in mpg well enough to calculate a 345 mile range?