Leaving the country won't help. For one thing, where will you go? I think you'll find that the US, even if tobacco is illegal, is still better than most alternatives. More to the point, it doesn't matter because the industries that produce our pipe tobacco will be driven out of business. Sure, you might be able to pay $100 for some tobacco some dude grew in his backyard, but I doubt that's going to be all that attractive an option.
Guys, we live in a society where you can be arrested without cause, everything you say or do can be monitored/recorded, and where the private sector is even less respectful of privacy than the government. And we have gone along with every single step of it --- it's not like it was forced on us.
Me? I'm stocking up in the hopes that once a week or month I can still enjoy a pipe into my old age. Maybe.