I and 13 of my oppos did exactly what you are proposing but in vehicles that could do it and with drivers that could do it!
We were using Bedford RLs with of course 4 wheel drive with cross country tyres.
All the drivers were Royal Marines driving instructors.
We just pealed off to the blocked lane and used it being careful not to go too fast and spray snow all over the cars.
We ran into heavy snow, about 6" depth, there were only 2 lanes on the oxford bypass at the time and the deep snow was on the right lane, the inside lane was nearly stationary because of the pile up of slow traffic.
When we got to base the rear drivers said cars were pealing off into the lane we cleared for them!
It would not be safe for Artics to do the same with normal tyres and also the dual carriageways always had a slight slope to the side of the road, any slight braking would send the trucks into the inside traffic blocking all the traffic on the bypass!
It woul be very dangerous to allow artics to try the same!