I have had a Canadian ID card when we went to PEI and Novia Scotia.
I just requested one from my insurance agent via chat. You only need liability on your truck... as said above the liability for your trailer is when it is connected to your truck.
One think I found out.... My insurance is for 6 month intervals. My insurance is renewed March 1 and Sept 1. If I am in Canada after August I will need a new card. I fulltime. My mail goes to Livingston TX. I have never had to have mail sent to me in Canada. I can probably get it sent there if I am in a campground that will accept it. I know I can download a temporary US Proof of insurance, but they will only fax it because it is made out manually. I asked if they could scan the card to PDF form and email it to me or store it online where I can access it.. They said no... I will be calling the main office next week and see if they can do a little better...
Anyone have this problem... My insurance is Progressive..
BC
BTW... we are heading there after Goshin also.. Plan to go to Calgary, Banff, Jasper, Lake Louise, Vancover then back into Washington state..