Great! Thanks for taking this one on, @vutny

I experienced some issues deploying the new solution: The Master loses connection to the Minion upon restart, which makes it print a "Minion did not return. [No response]" error and probably also aborts the highstate run for that Minion. I fixed this by adding order: last, which is what I also had been using with the previous (nohup-based) solution.

Two additional notes:

• Contrary to what the new heading suggests, this solution is not only helpful for restarts after upgrades, but for all restarts, e.g. also after changes to the Minion config.
• A similar procedure also has to be deployed for restarting the Salt Master.