Gizzy: MAW73 (where is he?) got some 18" Black Monza Shadows for £350, set of four. You could put some Conti 830Ps on these.
Asker, I understand you atre a southerner, and therefore has no understanding of the depth of snow Amanda is likely to find, during 'winter' (that's the time you southerners only hear about on the news) on her drive to work.
Believe me, I would NOT want 18" wheels with 225 wide tyres in conditions as shown in the YouTube clip I posted...and that location was only a handful of miles from where she lives.
If you NEED to go to work, and want MAXIMUM winter performance in snow as well as the cold...forget 18" 225 wide tyres.
Take the advice of VW and fit the wheels and tyres approved for arctic conditions...they will offer better protection and better grip in the proper bad stuff.
We all know 18s look better...but looking better when heading to work at 7am with 4" of snow on the roads, isn't the prime concern.
Amanda has already conveyed her lack of confidence in driving in snow...so my advice would be to give her the best possible chance of successfully getting to work safely, with the best grip possible, and the most protection from doing wheel/suspension damage should a wee slide occur.
18" wheels look far better - I know, my winter wheels are 18" but I don't have to drive to work, and I'll not be going out in the snow - but a bent Golf and a dent in confidence looks far worse.
Food for thought...