13 2m plants isnt really recommended inside, you should be ok with your holiday, I doubt that youll miss much if theyre in a greenhouse. If youve only just determined the sex, i would say youve got at least another 2 months of flowering before harvest, itll get cold but i doubt itll get too much for them, I know more and more people getting successful harvests outside here in the UK, sometimes not harvesting until november.
I hope this goes well for you mate,
take care,
mrmarijuanaman