The simplest solution would be to get some old mattresses or seat cushions, for padding, and push it with another vehicle.
Would you push a 71 clubman with another car only seperated with a mattress!!!?
Yes, I'm assuming you've pushed it with your hands or backside on a much smaller contact area.
Yes on strong seams or convex areas that won't deform.
If you push a mini up a steep slope using another car, the force will be taken by the bumper seam and I guarantee it will deform under such methods. And then there is the car pushing it...being modern and not broken, if the mattress was to slip then a plastic bumper would get quite badly damged from an oldschool metal effort.
Not great advice and I wanted suggestions on winch systems, not a Scraphead challenge method.