I have everyone’s house wireless the same so I can just go from my parents to grandmas to mine

You are not the only one

I do every time now for extended times I don’t know. The longest I had was 2 hours.

Keep your existing cable no need to upgrade. For new runs cat 6 is good for most people especially in a home. There is little to no difference in price of cat 5e and 6 at this point. I have seen where cat 5e is actually more.