Why not have the post office redirect it all to one of the kids or a relative you trust. Then they can vet it for you. If it is important they can send it on or read it to you over the phone. If you have internet they could scan it and email it to you. If you need any thing sent on to you just identify a post office ahead of you and the kids to send it there for collection.
This is a good plan for rego and insurance etc. Saves changing electrol roll and all sorts of other dramas.
We don't get mail! We have a very good friend who opens ALL of our mail, pays the bills that aren't automatic, and emails or phones us if anything urgent pops up (which it never does), or when she needs more money. We reccon this is THE BEST system by far, and we are on the road for up to 9 months at a time.