I have been running an 8' Fisher HD for 4 years now, I just put green keys in and crank them up a little bit to handle the plow, although I change my tires and wheels for winter/summer so I get it aligned after I make adjustments for the season.
Put the air system treatment in lines like semis do to get rid of water etc. or install an air dryer that runs the treatment into the system all the time in bad climates. You can get them at Kenworth etc. for trucks with air brakes. You won't have to worry about frozen lines anyway.