So you don't have time to practice organ today?
How about 15 minutes?
Or maybe 10 minutes or whatever it takes to play your piece just once?
Can you do that?
Or you'd rather skip practice altogether?
It turns out one missed practice session leads to another and another and pretty soon you'll have to start over.
Organ practice over time is like a chain of perls.
Don't brake the chain.
PS Video of Estampie from Robertsbridge Codex for my Earliest Organ Music Collection