I'm more likely to think if I've got the cash for an extended tour, I can probably afford to replace the down jacket. Take an old one and donate it to charity or a homeless person when you no longer need it. I left my sleeping pad in the freebie section of the hostel in Reykjavik, because I didn't want to deal with getting it home.

As a diabetic, I'd never try to ship my insulin abroad. Hand carry it, and if you can't take enough, make sure when you are getting to the end of the supply, you are in a country where you can visit a doctor and get a refill, get home to get more, or have someone bring it.