1300 sq ft first floor condo that was completely redone with insulation etc. in 2012. Gas stove and tankless gas hot water heater. I put in a Sensi thermostat that I got on a Black Friday MassSave sale for like $10 or $20 - there was no C wire so couldn't put in one of the fancier ones. At night and most of the day it's set at 62, in the morning and evening it's 70.

My January bill was for 61 therms, came to around $153 (same rates as your bill).