How do you manage to stick to your habits under changing circumstances? Visits to the in-laws, visits to friends, holidays, etc.

You have to think about it ahead of time and come up w a plan that will work in the newsituation. Basically I have patience with myself that it might not be exactly what it looks like at home or the perfect way I would want it, but if I think ahead then I can make a plan to get it done someway that I know will actually work

I always carve out alone time. My friends and family know this and I wake up earlier than they do to have that quiet time. I also go to bed earlier to avoid the long nights of drinking.

It's not easy, but I have crafted my core habits to be applicable anywhere I go. At least the morning and evening routines, I have thought of variants of all the habits that can be done anywhere, without the need for a specific environment. That being said, there are habits that only make sense in certain circumstances, things such as deep work doesn't apply (in my opinion) to holiday times. In this case I have made sure they are in a separate routine and I simply pause the reminders when I'm in a circumstance in which those habits don't apply.
Finally I'd put in a little word about boundaries, when visiting family or friends, I do struggle with setting and maintaining biundaries. However I have learnt to carve little corners of time. For example I stay in my room when I wake up and do my morning stretches before showing myself and having the day start. I also say I'm going to bed earlier than I actually do, so I can have a short yoga session before sleep…