I have been checked maybe a dozen to 18 times in the past 30+ years. Most stops are fine, but I have met a few guys who must have woken up on the wrong side. The last check was on Red Lake in the winter. Went fine. Man, that guy drove up quiet and knocked - came in stealthy.
To the point above ... I had a warden wanting to search my entire truck. I told him have at it, but he needed to put everything back as he found it. You better be sure you are legit if you take that position. I was 20 years old and he did not like my position - but he did back off.
Another time I had a warden tell me we had too many hen pintails ... I then taught him what a hen gaddy was ... I said lets take photos of each bird with you holding out the wing... I will need this if you write me a ticket and we go to court. He was POed at first, but then realized we knew our stuff.
Most of the time though the talks are casual once the regular checks are done.
In the Dakotas random road intersection mandatory stops are more common ... I have read the SD ones are pretty good at catching violators.
In MN I believe many wardens are busy with special ops research and investigations on habitual poachers, violators, responding to TIPS, etc... Outside of opening weekends during hunting season I do not believe most wardens are driving around completing random stops.