I can't tell enough difference between high and low to worry about losing low. I did, however, replace my thermostats with the Coleman brand (I don't want to worry about warranty issues). They were more expensive yes, but operate on 12v.
They have been working full time since August 2010.
2006 GMC 2500HD CCSB 4x4 Duramax/Allison, Titan 52 gallon fuel tank, Prodigy Controller, B&W Companion Hitch
2010 Jayco Designer 35RLTS, Cummins/Onan RV QG 5500 EVAP, Progressive Industries EMS-PT50C, TST Systems 507 TPMS, RV Flex Armor Roof