Move cat away from family or bring all of them?

For context, I have 3 cats currently residing at my families house: 1 mom and her 2 kids. They are very outside-oriented currently, but as proved by winter, they can definitely adjust to being inside most if not all of the time. The cat I initially had plans to take to a new apartment is one of the kids.

I finally have the opportunity to move into a place that is pet-friendly and am really looking forward to being able to live with my cats again (because my family hate them and now has dogs that freak them out). However, I am wondering if I should bring my favourite of the three and leave the other two at home, or if I should bring all three. The kids have been living in the same place literally since birth, and I have no idea how they would adjust to being separated. The place I am moving to also isn’t huge, but would still be enough space for all of them.

I am basically just very unsure if I should move just the one, or take all three with me. I plan to get a ton of entertaining stuff for them in the new apartment and am fully prepared to spoil them to help with adjusting.

Will the other two be okay if one of the cats they’ve lived with their whole life just disappears one day, or is it better to bring all three?