I called up both Toyota of USA and Toyota of Canada. The good news is Toyota warrantis are good in all of North America. So I dont have to worry about this. What a relief.
If you are looking for a V8 they do not come with a weight distribution hitch as standard in Canada - tow limit is 5000 lb unless you add the WD hitch aftermarket. The V8 does come with transmission cooler as standard however. (I only just realised there was a difference when another thread here started talking about 7000lb tow capacity on the V8s and I realised I was missing out on something!)