This is just from my own recent reading on the topic, I'm no expert and as this is a serious legal issue please assume I'm totally wrong and start from there.
There have been 2 recent changes in New Hampshire, one is a change to the ccw law and the other a court ruling that applies directly to non-resident licenses.
New Hampshire seems to be going towards no license at all for ccw
h ttp://nhpr.org/post/nh-senate-passes-concealed-carry-gun-bill
"New Hampshire would join the ranks of Vermont and Maine for permitless concealed carry. This would mean vacationers, tourists, hunters, and residents could travel over half of the geographic area of New England before needing a concealed carry permit."
h ttp://concealednation.org/2017/01/new-hampshire-permitless-concealed-carry-passes-senate-and-goes-on-to-the-house/
That is for born US citizens I'm sure, a Canadian would still need to apply for the non resident permit but even that's been made easier with the recent Court decison,
***UPDATE 10/25/16*** Please be advised that due to the New Hampshire Supreme Court opinion Bach v. New Hampshire Department of Safety, ___ N.H. ___ (No. 2014-0721, decided June 2, 2016), Out-of-State Residents applying for a Non-Resident Pistol/Revolver License are NOT required to supply the Resident State License Number on Form DSSP 260 and are NOT required to supply either a copy of a valid concealed carry license issued by the state, county, or town in which they reside OR a letter from their local police department, as described in Saf-C 2102.03(c) and on the reverse of Form DSSP 260.
Thats from page that issues the permits, so today it seems you'd send in the non resident pdf form and 100 bucks and await the card.
h ttps://www.nh.gov/safety/divisions/nhsp/ssb/permitslicensing/plupr.html
Of course that's only if this actually applies to Canadians, but in the past I've seen threads saying NH was accepting the PAL as a valid "state permit" and as the rules seem to be relaxing they don't seem to want a copy of your PAL anymore. One would have to try and see.
Interestingly, the need to prove you have a locally issued license matters when you try for the hardware rather than the ccw permit
h ttp://www.gencourt.state.nh.us/rsa/html/XII/159/159-8-a.htm
The recognition that the 3 New England states have allowing easy ccw between them may only be for US citizens, a Canadian might be restricted to only NH proper when using the NH permit, I don't know and I would certainly want to be 110% clear on that before I started wandering across the state lines.
