PGCE is a ton of paperwork and like Sparkly said, it depends on how organised you are.
When I did mine 3 years ago, I was conducting the Uni wind band once a week and also playing for a championship section band twice a week as well as the Uni Orchestra which meant I was out 4 times a week for at least 2 hours. It meant that I was doing all my paperwork either in my frees or as soon as I got in from school before a rehearsal or skipping the pub afterwards and doing when I got home, sometimes till 1am and then having to teach the next day which was a killer!
I found it really hard on my first placement but a lot easier on my second - down to a different attitude from the mentors I had in both schools so wait till you get to the school and see how it goes!
I wouldn;t decide until you find out your placements and have sussed the school out a bit. If you know someone who is on the course already, have achat with them because each PGCE course and subject differs - I said my paperwork mountain was massive but I didn't have to do as much marking as the Matsh guy who was marking for 4 hours a night!
If you are placed miles away from where you currently live, you might have to relocate anyway so it could be impossible.
Best thing to do would be to let your band know that you might not be able to carry on with as much commitment due to work now and see how it plans out between now and september!
Once you've got the year out of the way though, it is a hell of a lot easier!!!!