My daughter's house doesn't need open central air system vents upstairs during the winter months.
Heat flows up an unrestricted staircase and many times, over-heats both upstairs bedrooms.
Sadly, during the summer the upstairs bedrooms are over-heated (solar gain)
and the cold air from poorly installed central air can hardly be detected upstairs.
I think the lesson here is, not all HVAC installers do a good job.
Electric (and oil) baseboard heater zones are sometime turned up when that area is being used..
If you are sleeping upstairs and no one is going to be downstairs for many hours,
I would just turn up the baseboards in the bedroom (19C ??).
Leaving the downstairs heat turned on for heating upstairs is a bit wasteful,
because you are heating rooms downstairs, while they're unoccupied..
IMHO, the idea behind zones, is to heat the area you are currently using..
