Sometimes it’s worth the big dramatic fight.
Sometimes just letting people know you’re not going to be very reachable for the next few months, neatly sidesteps that. They want to know why? You didn’t want them to worry, it’s nothing major, just expect to be busier than usual.
Sometimes it’s better to just let things happen organically. Distancing yourself purposefully, but also gradually.
There are a lot of different ways this can go. Informing them in advance? Is only one way.
...One of the patterns that distance can teach is not “having” to tell your business to any and all. You don’t “have” to inform people of your plans before/during/after. No one is owed an explanation. We give those to people we care about, but are not required to. Even if it’s a job/boss, you don’t have to tell them you’re not coming in this week. Being fired is the consequence of that, so it’s generally avoided, but it’s not like they’re going to drag you out of bed and force you at gunpoint to go to work, or to call in. Doing either is a decision we make.