The ferry to Vancouver Island for your rig, toad, and kids is pretty close to $200 US each way, maybe even more.
If you all have bicycles, South Beach in Oregon is an awesome place to bike around in. Fort Flagler in Washington State is another the kids would really enjoy. That is up the Olympic Penninsula, then go to Camano Island and come to North Vancouver at Capilino RV Park. Pricey and busy, but you can enjoy Stanley Park, Lynn Canyon Suspension bridge, maybe even a gondola up Grouse mountain.
With your toad behind you, do not intend to go up past Pemberton. There is a beast of a hill climb there, and it's not good on heavily loaded rigs like yours.
To get from Vancouver to Waterton is a good two days. About six mountain passes to go over and a busy highway.
As others have said, stop and enjoy the park and place you are in. Distances are huge up here, you won't see anything unless you stop and have some fun.