I already have a major question!!!!!!

My parents are looking to retire in Oregon and debating between Brookings and Newport. I may live with them in Oregon, so these cities are two musts for me to check out. From home to Brookings it takes 5 hours, from Brookings to Newport it takes 4 hours, and from Newport to Seattle it takes 5 hours. How do I determine how long to spend in Brookings and Newport when I have an entire loop to go through? Is a day sufficient? An overnight? Two days? Mind you, I may live there someday so it's important I stay long enough to get a good impression of what it may be like to live there, but I also have to take into account that I have an entire loop to go through, but I also don't want to feel rushed.