Karl,
I've crossed that border in various places all my life. I've done it in various boats, airplanes, cars and RVs. No motorcycles, bicycles or walking yet! I've delivered Cessnas to Canadian dealers, dealing with taxes. I've flown "experimental homebuilts" into Canada. BJ and I spent our first married night in Canada. She was nearly a child then! I've not kept track, but I might have had near a hundred crossings. I’ve always been passed with the worst case taking about two hours coming home when the inspector left the airport to go home for dinner as I was landing!
The only thing that really counts is weapons, dog shot/health records and passports. There are passport substitutes, but not as many as there used to be.
Generally speaking, you have an estimated 85% chance of going north so smoothly, that you've love the Canadians. They seem to welcome us as tourists. There is about a 15% chance you will be randomly selected for a little extra attention. They don't seem to get concerned over honest mistakes. They don't want overt smuggling or criminals. For example, I once went through with a few partially consumed bottles of booze. Nobody bothered to add it up to see if I was exceeding the quantity limit. If there is a restriction on lettuce, bananas, limes or something, you will be politely asked to give it up. They generally seem to apologize if they have to ask you to give something up.
Generally speaking, you have an estimated 15% chance of coming home smoothly. You can expect long lines and surly inspectors dressed in Kevlar that are well armed and with an attitude that work slowly. There will not be enough inspectors for the workload. Many seem mad at you for having a vacation while they have to work. They have not learned from the friendly Canadians! It will seem like their goal is to get you to write your congress people to get more guards, less work, higher pay and longer coffee breaks. Have something to do while you wait in line. I speak from experience when I suggest you do not let frustration be irritating. The moment you enter a line at a US border crossing you give up all control. There is not room to turn around and come back the next day. Pity the people in line that don't have their toilets with them.
That said, once they (slowly) determine that you are not a criminal, you will be allowed to return home. Even people who have not read the regulations seem to get home the same day they try! I can't imagine how we treat people without US passports that should be treated as guests.
One last suggestion..... Ship me all your extra fine Scotch and Bourbon. I will try to store it for your return and deliver it to you in Oregon when I see you. Drink Canadian while you are there.