Not much snow yet so I'll throw this out from last December.
Not really good at linking, so the first three are videos and will probably kick you off to photobucket.
Think the 3rd one down sums up the day the best.
Actually, one old book:
DOC: http://royallib.ru/get/doc/lavrentev_v/ ... am_bam.zip
HTML: http://royallib.ru/get/html/lavrentev_v ... am_bam.zip
says that you can make a rigid connection between two cars and rear car, using the path left by first car, will propell first car, and thereby this train will move in the snow.
There's even a percentage of efficiency of such a method.
You can find this place in book, the text is under the heading Вождение автомобиля по заснеженным дорогам и снежной целине
On this photo, rear car can push the car in front and help it to make the path, while using this path.
With these two Jeep, pushing happens quite often and works very well. Also during this run, pushing was the only way the Jeep could move, one couldn't get enough traction to push thru by its self. Being pushed wasn't always enough either, the picture with just the tops is me at the closet tree because they are both stuck.
I've see old school pictures of rigs hooked together with tow bars in "trains" of 5 maybe 6 at once. I heard it worked well but bent a lot of tow bars and once stopped, it was a hard to move anywhere.