Simply put... No
There's still only a few Cellular enabled smartwatches available. They do take a sim card and you can use them without your phone being present BUT you still need a phoned to be paired with it to set it up via the AW app (or Gear App if it's a Samsung Gear S watch) and sync accounts etc. So a cellular enabled watch is still really designed to be a companion to a phone. You can just leave your phone at home MOST of the time and use the watch for calls etc but not completely ditch your phone altogether
Because of that reliance on being paired to a phone it's almost impossible to use with a Windows 10 PC. I'm not sure if anyone has tried doing it through BlueStacks on a pc which is an Android Emulator for the pc?