Just received my bill for Jan. 2021, and it DOUBLE...

Just received my bill for Jan. 2021, and it DOUBLED!!! There is NO justifiable reason why this would happen! I have not changed ANYTHING with my routine, and I went from 800 kWh to over 1600 kWh. According to my MTEMC statements the average low last year was 40* and this year it was 37*. I own a 1300 sq. ft. home with a high efficiency HVAC unit and water heater (both installed three years ago).To say I am an extremely unhappy and frustrated customer is an understatement!! The internet is "blowing up" with my very sentiments. MTEMC needs to provide an HONEST and plausible explanation!!