It really depends, on so many things, but as long as you feel safe it works, stay as long as it works really, not much else matters, can be days to years
I'd say always have plan B and plan C in case things go south
I would never bank it all on one spot, and wouldnt get too comfortable, always having the most important stuff on you, what you leave at the squat you are basically ok with losing
I got all my stuff stolen because I got cocky, now I only leave my blankets and a cheap 20€ sleeping bag there
but im assuming here, squat not like a furnished apartment/abandoned house, more like just abandoned building, no electricity
if you have a better squat and replace the door lock and all, then as long as no one starts snooping and asking questions, it works
even then you can pushback and claim residency or just dip, depends how you want to do things
I think its an art, if you look presentable, are nice, polite, answer questions it goes well
its important to assert boundaries also, people can be very rude here, basically just because they are suspicious they expect an answer to any question, like.. you want my social security number too? damn
so I always act politely but firmly, asserting my boundaries, this in a weird way legitimizes you in their eyes, even how you move and eye contact/greeting is part of it
if you slink around people will get suspicious
also in my experience the nicer I was, the more questions I answered the more trouble I got into, the more info they got the more paranoid they got basically, ignorance really is bliss
and you can just be silent at stuff too, try to put yourself in a perspective if you actually lived there and how you would react to someone questioning and investigating you (which I think makes it possible to transition to actually living there too, if you tell them youre squatting it doesnt go well, but if you confidently assert you live there, thats different)
Thats why its an art, you basically want to look normal and inconspicuous to the people in the neighbourhood/area, not standing out and if someone asks you something, skillfully navigate it
ofc if you are in a remote area/have a hidden way to enter it doesnt matter