From the diagram you just need to move the NAS so it's on the same switch as the PC. The rest of it should be good enough (even if it isn't ideal).
The NAS I can manage, it's more when the wife is watching Sky Q upstairs and starts rewinding/fast forwarding it causes my PS5 online games to lag.
Not sure the TV where we stream films from the NAS will behave if I move it upstairs.