I have found yesterday interesting feature, which might partially solve problem with using DSW on different day than suggested.
I have scheduled Half-Marathon in my calendar as Primary event for mid March. In a plan settings I have selected long running days to be Sat and Sun
On Saturday I have had suggestion in plan overview to do 1h28m Long Run @ Zone 2
As there was a lot of fresh snow outside I decided to postpone this until Sunday. I have entered into Events -> Daily Suggestions -> Select next day (Sunday in my case) and -> Do Workout of 0h46m Base run @ Zone 2
I was positively surprised that DSW Long run was automatically rescheduled to Sunday.
For clarity
What I have had yesterday (Saturday) in Events glance -> Daily suggestions:
Sat Long run - 1h28
Sun Base run - 0h46 <- I have pick this one
Mon Base run - 0h46 etc
At least I do not need to created Workout with HR Zone target manually for today.
I will keep checking this for other days when I have scheduled eg. Threshold or Sprint rund if those will be moved as well.
Could you share your observations in reply, please?