Bringing up cold water temperature

jfleming

Tap temperature gets down into the low 40's where we live in the winter. For a variety of reasons, I'm looking at whether there's a solution that lets me:

1. Have a higher baseline cold water temperature (e.g. 60 degrees) in the winter
   
2. Doesn't increase the cold water temperature in the summertime (baseline temp is ~65)
   

On the face of it, a thermostatic mixing valve seems like the solution, but this seems like a use case that thermostatic mixing valves aren't typically designed for.

hot_rod

Most thermostatics have a low range around 80- 85°.
What is the reason for bring the cold temperature up? An un-insulated galvanized well tank near the water heater would be another way to increase temperature. Let it warm from ambient temperature in the room.