I haven't heard any of the NPC's mention it, but are there dragon attacks in the other Imperial provinces? Or are they only in Skyrim? I'm pretty sure they're only buried in Skyrim, but after they get resurrected they would be able to spread rather quickly to the other provinces.

Dunno, I do know that the Oblivion gates weren't restricted to Cyrodil though

Whether there are or not, the Thalmor will claim the credit of putting them down.

lol

Probably a few in the provinces bordering Skyrim. The dragon burial ground is in Skyrim so that is where they are resurrected. But nothing is stopping one from flying over to Cyrodiil and nesting above Bruma.

I'm pretty sure there were a few lines of dialogue mentioning Oblivion gates in Skyrim, or at least on the borders. Could be wrong of course but I can swear I remember hearing it once.

On topic: It's a possibility but not really likely, I think they'd stay closer to Alduin, once the Dragonborn was dead then they'd move into other provinces.

I dont know..
I heard someone talking about a dragon in vvardenfell.
Here on the forums

The Bards sing that the dragons are gone when you beat Alduin. But they are still in the game. So I believe they will disappear gradually and if they are in other provinces it isn't for long.