You certainly are optimistic - even 20km on your second day would be a big day:)
I don't know that waxless would have helped you if it was -10 though. Those are not great waxless conditions and usually waxing should be easy at -10. Are your skis too stiff? Technique refresher to make sure you are doing a proper weight transfer? Wax wearing off too fast (use a base binder)?
Nicki will respond to these questions and more when she does her next ski in one year's time (her third in three years!)
To be honest, Revy, my rusty technique is more of the issue than the wax. I just like to blame the wax.