Having lived in Minnesota for nearly 50 yrs of my life, I lived in many places heated with boilers and hot water radiators. I don't remember freezing to death and got a chuckle about needing to top off my antifreeze, even though 20-30 below temps were common. I went to several schools that were radiator heated. Once again, never froze if I wasn't seated next to the rad. Not a fan of hot water heat mostly due to the lack of vents, so adding air conditioning was a problem, but a properly maintained hot water system is different then what some have said here. Many people painted the radiators which reduced the efficiency and they can be insightly. I don't know if a hot water heater would work anywhere as well as an actual boiler.