Ferry to the Island is less than 2 hours - if you are taking your rig you might want to make a reservation as an "Overheight" I went over last Summer and it cost me nearly $450 return with the fifth wheel.
http://www.bcferries.com/
Not that many campgrounds around Vancouver - Capilano and Hazlemere are good, Hazlemere is one of the top 10 Good Sam parks in N America.Also Tynehead, Dogwood campground and Pacific Border campground.(Right next to the border crossing)
http://www.tynehead.com/
http://www.dogwoodcampgrounds.com/
http://www.pacificborderrvpark.com/
Free casino overnight in Rolling Hills Casino, Corning California. - Tulalip Casino north of Everett and Seattle in Marysville on I5. 7 Feathers in canyonville Oregon is a beautiful park - there used to be free overnight at the casino of the same name but not sure since they opened the RV park there. You cannot overnight at rest stops in Oregon, Washington or BC.
You are supposed to have a rabies certificate for your pets but in 40 years of going back and forth (I live only 10 minutes from the border on the Canadian side) I have never been asked for one. Also fire arms are prohibited from entering Canada except for some specialized uses (Gun club competitions etc) - when you arrive at the border there are 2 crossings - the main one on I5 and another one delegated as a commercial truck crossing about 2 miles east - you can cross at either and I would recommend the truck crossing as it is usually quieter.
I would also recommend a trip north of Vancouver to Whistler Mountain - about a 2 hour drive. There is a beautiful RV park there. You will pass a number of Provincial Campgrounds (Like your state park campgrounds) but very few have hook ups and the majority of the sites are small.
Have a great trip. - if you need any other specific information contact me through this site.