But just in case, you can fly UA on a 1 way award domestically. You can also use these miles for partner redemptions on any of the StarAlliance partners. You can fly within Asia, Europe, South America etc if you’d like. Plenty of options. Home - Star Alliance
Using your miles for a magazine (as noted above) is a good way to extend your miles, but usually a bad redemption.
Another way to extend time before miles expire is to join their dining program. Eat at one of the restaurants in the program, get a handful of miles, and you’re alive for another year.
What’s the easiest way to swap miles? I have about the same number of Delta miles I would swap for United miles.
Just have some non-flying activity (dining for miles is a good suggestion) to extend the expiration date of the miles.
They have the most value used for a flight when you NEED them. 12.500 miles is the low UA one-way redemption.
I live in Portland so Virgin plus Alaska covers much of the US. United, especially out of SFO has left me on the tarmac for multiple hour delays for the last time. I was trying to keep this positive though. I’m sure other folks have had good experiences with them. Just not me.