Also - season finishes mid May and starts early-mid August adding an extra 3 or 4 weeks to the break/pre-season.
However, I'm not in disagreement with you.
I'm just pointing out the errors as challenged, and with relevance to Motherwell, rather than Scottish football/Celtic (no one else is likely to be in Europe around Christmas) as a whole.
edit - and you'd probably find more pre-season trips abroad rather than staying at home in the winter