moving out with my cats

Hi guys, my family has been living for my entire life in a villa in rural southern Italy. I’ve moved out in the north for university in september 2025. My father has gotten a new job so we’re gonna all move out together in an apartment really soon.
My 3 cats (female 8, female 7 and male 1 years old) were all used to spend all day outside and come in the house whenever they wanted, and now that we’re gonna bring them with us i’m scared that will become shocked because or the moving out or maybe they will even develop depression or something like that, because they’re gonna spend their entire lives indoors. I was thinking of buying a leash or something and bring them out a few times a day with that but I’m still really concerned about how they will react so any advice or experience about that are welcome
also i wanted to ask considering that i think we’re still gonna pass summers and christmas period in our old house, if it’s possible to bring them with us every time or that would be too stressful

sorry for my english and thank you in advice