Hm I’ve done Bircher museli in summer but if you heated it up in winter wouldn’t it get all gluggy and weird? I should give it a go anyway.

There is a microwave at both workplaces although the one with the longer commute is trickier because the shared kitchen is often busy (and extremely bare bones). I’d need to bring my own nondairy milk too, maybe if I pre poured it into smaller jars