Flagpole process is usually always very smooth.It was about a 3 hour drive from Calgary and we arrived there at about 1230.
Told the US border agent that we were there to flagpole and was told to park up and go into the building. There was one family already waiting and they left after about 5 mins, we were then called up by the Officer who asked if we were entering or just there to change our status, I told him we were just changing status and he handed back our passports and said as we were from a visa exempt country there was nothing to do by them and just drive back following the return to Canada signs.
We drove up to the Canadian side told the Officer we were there to land, he asked us to park and come in. Inside the family that was at the US side were just finishing and we were seen straight away. We were asked if we had every been arrested, denied entry to Canada and if all the details on the COPR were correct. It was then a 5 min wait while they did all the admin, he gave us back our passports with the copy of the COPR, told us our supervises had been cancelled and welcomed us to Canada.
All in the whole process took about 30 mins and the officers at both sides of the border were very nice .
Did you declare any money or goods to follow for your parents? This issue is not came up this forum yet, but would be something useful if they want to bring money or goods in future.