The problem of wheel spin boils down to the percentage weight distribution on the front wheels and, just as important, the make of tyre.
Of course, a front wheel drive car inherently suffers from a certain shortcoming in this respect but there are ways of avoiding problems, especially when manoeuvring on a slippery surface:
1. Gentle use of clutch and accelerator (the obvious)
2. Make use of any momentum you've got, i.e. once you've got going, keep your speed and don't stop (requires a bit of extra foresight to assess the conditions ahead).
3. If you need to move off on a surface which offers limited traction, place the car and caravan at right angles and not in a straight line.
By observing these rules I was able to tow with a Vectra for years without a problem. Only on one occasion did I need any outside assistance and that was when I tried to get up a steep wet ramp on to a ferry in Norway while at the same time towing a caravan right on the weight limit. But even then we made it by having two people sit on the bonnet until we got started.