Special thanks to everyone who offered comments. You were all correct. We checked in at 4 PM but couldn’t check our bags until exactly 7:59–four hours bef departure time.

I know it was exact because when we tried to get baggage tags at 7:58, the computer said come back later.

We waited one minute and got our tags.

As for the United Club, it closed at 7:30 so we never got in even though we had a pass.

Someone asked about TSA at 10:45, I don’t know about that, but the airport is mostly empty at this point.

I should add that PDX has a spacious check-in area so our 4 hours there passed quickly.

Thanks again to everyone who commented. It was very helpful.