Last summer when Ottawa signed both goalies to a three year deal, I said to myself it was just a matter of time before Lehner takes over the number one position. It only made sens as it's way easier to trade an elite goaltender like Andersson when he's already lock in under contract.
Now, I don't think it will happen as planed since it is obvious that Lehner is not ready to take over the number one position. If Ottawa would trade Andersson now and givie Lehner the number one position and it doesn't work out, not only they will compromise the rest of the season, they may compromise the future of this team.
For me it would be either try to get the most on the trade maket for Lehner (maybe a young back-up for Andersson + a D) , or stay status quo for the goaltender position.