First few years I parked everything. We dabbled with occasional winter work.
Last several years we have too much business. Now we even schedual jobs for frozen ground. So...Make sure you have a shop/garage you can bring in equipment to thaw and work on out of the elements. Plowed dump spots are required too. A mini with a bucket is awesome to clear snow out of the way.
Once a year we pressure wash, spot sand blast and paint. Fluid film or motor oil the undersides after pressure washing. The salt the piss out of the roads around here.