I have a new Verizon iPad that I want to use in Canada. I can't find a definitive answer online to the following and it would be great if someone could help me out. I want to know 1) which carrier I can use and if I can just buy a micro sim from that carrier and pop it in? And 2) do any of these carriers support LTE for the Verizon US iPad?

I thought Canadian LTE connectivity was advertised by Apple somewhere on their website.

That depends if you have an iPad 2 or "the new iPad" aka the 3rd gen iPad. All of out carriers that support the iPad are gsm. From what I'm aware the new verizon iPad supports gsm roaming while the 2nd gen doesn't. Easiest way to tell would likely be if you have a micro-sim card slot, if you have one you should be good to go, if not you are sol.

As for the carriers the main ones are telus, Rogers, and bell. I'm not sure about plans or if some of the smaller carriers also support it, they might as most are owned by the big three...

Specifically with respect to lte connectivity I think ours as gsm lte carriers are compatabile with the AT&T 3rd gen lte iPad but not the Verizon one. But you should be able to connect at 3G speeds.

I wouldn't be surprised if a US provider had cheaper roaming rates in Canada than the ones offered here!