It looks like a one way ticket is half the price of a round trip ticket (about $320-340 only outbound vs. $700 for the round trip). So you don't have to worry about using miles for a one way now and then getting stiffed by trying to purchase a one-way with UR points (or cash).

If you can get the saver award, using miles is better than buying the tickets using UR points. And if you can't, it looks like a wash. Since that's the case, I would lock in what's available now and then try to pick up the outbound by checking regularly. You could even try biz/first or a standard award (either way it's 25K miles for that one way) which I think would still be a tiny bit cheaper than using UR points to buy the ticket.