You can start the paperwork from Ireland but then you'd have the added burden of proof that you are actually going to move to Canada when he gets PR. If you go to Canada on a one way ticket, with your husband as a tourist, there is a chance that your husband could be refused entry. Normally 2 way tickets are cheaper anyway or you can get one that is refundable if you don't use it. He would not be able to work until he gets the PR but maybe he could volunteer
