I have a similar dilemma, of a 600km cycle "holiday" over 24/25/26th of December, crossing most of Germany. There is a good chance of snow and ice. I have 42mm studded tyres for my bike, but the prospect of a 230km day on them does not appeal
I've done 90km on them, and that was hard. I am a lot fitter now, but it's still not something I'm looking forward to.
If you can avoid doing it on studded tyres, do so.
J