electric blankets do not help your water pipes from freezing up.
Earlier this year in January we got down to -8 f and anytime we get below +10 f I have to run space heaters in my laundry room and trickle water into the laundry tub. I use a small space heater under the kitchen cabinets to keep my dishwasher from freezing up. I also crank up my forced air furnace too. This house I am currently has a slab floor and very poor insulation. When I lived at another place with a basement I never had to worry about the pipes freezing as long as the furnace ran