Welcome to OCDO! Stick around and you will learn a lot!!
I think you should OC. The chance of needing your gun is 0% until it is 100%. It may be better to go armed and risk offending your family. They will thank you if something happens. I have OCed for four years without incident. There is nothing for your family to worry about related to OC. My mom was worried recently when we took a trip to PA because I decided to OC. She got the opportunity to see what happens when I carry on a daily basis. I think it changed her opinion a lot.
I would recommend posting in the specific state forums of the states you will be visiting. That is the best place to get accurate information.
No matter what you decide, let us know how it goes. Good luck!