Ok.....figure on 90 mins, it will probably be less. It is seldom more. Yes, it could take longer, but that would be unusual.
But....be careful. If your flight lands, on-time, at 4:30, that gets you to the gate by 4:45. That gets you to POR by 6-6:15. IF your flight is on-time. The one time I needed to be someplace within 3 hrs of landing was the one time my flight was delayed 3 hrs! I had paid for a function at the CR...with Jim Korkis as the speaker I was staying at BLT, so it wasn't going to be an issue. The function was 3 hrs after landing. But, we didn't take off from Boston until the time we 'should' have been landing.....3 hrs late! We got to BLT and checked in. I had a friend who went to the function...she texted me to tell me they were finishing up and Deb and the group were heading to CoP for the rest of the get-together. Met up with the group as they walked to MK!! So, stuff happens. Don't make plans for anything you have to pay for, or do t want to chance missing if your flight is delayed.