Well, we have several folks who have bought Titans to use in Alaska.  And, if they work there then they should work practically anywhere!  Seriously though, see our page which deal with Titan tankless water heating in the northern parts of the United States at "Titan in the Northern USA".  The N-120 can produce really hot water but has its limitations as described in the heat rise charts.  You expect to get up to a 64 degree heat rise in one and one-half gallons per minute with an N-120 unit.  At that flow rate you would definitely need a water conserving shower head rated at 1.5 gallon per minute (gpm).  No other faucet or shower could be running without lowering the overall temperature at the outlet of your Titan.  Add that 64 degrees to 45 degree water and you would get an overall hot water flow at the outlet of around 109 degrees.  Note that people usually shower in water heated to 100 to 105 degrees Fahrenheit.  Hotter water and more flow requires a larger Titan unit.  Go to:  Titan In The Northern USA  for more  details on our larger N-180 and N-210 Titan Tankless Water Heaters and heat rise vs. flow rate charts.  There you can find maps showing the climate temperatures of the USA and well water temperature maps which can be useful in determining the size of your Titan.

The most important feature of tankless water heaters is their ability to a provide a never ending supply of hot water.  Care must be given to selecting the tankless water heater for your area and your hot water needs.  You must choose a unit that can overcome the temperature of the incoming water at your location.   Careful consideration to the number of gallon per minute of heated water at that temperature rise is critical to your enjoyment of a never ending hot water supply.  Note that when using any tankless water heater:  The more flow you expect from your unit, the cooler the hotter water at the outlet.  Please refer to the temperature rise vs. gallons per minute charts in Titan in the Northern USA.