Some days I just have 1 Huel shake, also if I fly somewhere that day is often a non Huel day. The 12 days is a average of all my 10+ day trips. Your math is correct its simply my observations during travel.
I’m a mich lighter traveller (but then not exclusively Huel while I’m away). I travel with 10-12 scoops in a (doubled) ziplock with a scoop and then just a shaker. I’ve tried travel blenders in the past but honestly so long as you follow the counterintuitive advice to put the water in first, not overfill etc then you’re golden. I always try to find ice wherever I am which vastly improves the experience for me.