Start visiting the area now- to slowly get an idea of where you will be working and how much of a drive time you are comfortable with. That said, learn the peak routes that have the highest traffic during your morning and evening times. I say that because not only is your time valuable, but you can find great homes just a few miles out of your original desired area because you are willing to drive another 3 minutes to work, and save some money because of city zoning or other related impacts.
Furthermore, I would encourage you to rent first- for 3 months or so, if you can find a great place that soon.
Start looking now though because demand is high for good rentals with less than an hour commute into Portland.
If you ever have any questions on the area, neighborhoods, traffic patterns, anything- I'd be happy to share my own experience and advice with you: email@example.com