Possible to save a dried out tin??

Jim:
If the tobacco is springy and has give then fire up a bowl.
I don't know what resources you have available but earlier this week I purchased eight 10 gram sampler packs of the new Comoy's Cask #1 Double English.
They were toastier than I care for so I dumped the packs in one of my wife's Pyrex baking pans. I saturated a couple of paper towels with distilled water and stretched them over the top of the Pyrex pan and then sealed the whole kit and caboodle with Saran Wrap. Eighteen hours later I had moist, pliable tobacco which required about thirty minutes worth of airing time for me to smoke.
Hoss, if you're in the field or at a base with a field kitchen, try and find a sealable sandwich bag - or larger - and do the same thing as Rogue suggested. I'm not a big fan of laying anything wet directly on tobacco but that damp piece of paper towel will work wonders unless you've inherited "dust".
Take care and get home safe.
Fnord/Also a Jim

I successfully rehydrated a ten year old tin of "Early Morning Pipe" by laying a damp paper towel over the open tin, then closing the lid over it. 24 hours later the tobacco seemed a lot more moist.

Trailboss I love those rehydration discs that are about the size of a quarter but twice as thick. I was very impressed when I put one in my tobacco pouch to re-animate some Condor and next day hey presto just like new!

You don't want the tobacco to stick together when you pinch it between your fingers.I suppose in the desert it's going to dry pretty quickly. If you wish, you can simply pack a bowl, place your lips over the tobacco in the bowl and blow some breathe through it. That will likely give enough moisture to give the blend a try.That will also give you an idea of somewhat proper moisture too. Good luck, stay safe!

Mike S.