Holiday Workouts

I'm going to Poland next week for 3 weeks to vist family in-law.
Sticking to my regular exercise routine will not be possible (no access to gym and probably too cold snd snowy for running).
I'm only just getting back in shape after a bit of a christmas blowout, so really want to make some effort while I'm away so that I dont come back as a giant blob like I usually do. I was just thinking of 30 day shred and maybe running up and down the stairs of the apartment building, wondering if anyone has any more ideas of more effective workouts that could be done in limited space (my mil's flat is tiny).
Thanks!