Honestly, I generally think it's a better choice to sacrifice Hawke. The Wardens will be needed again, and I do not trust keeping the Warden's around without them having a leader that isn't an idiot (I wish there was a choice along "Okay, Corphy is still around, so I need you guys to move out for now in case he takes over your minds, but stay safe and come back and do your jobs as soon as I take care of this idiot" rather then "invite them to stay around someone who may mind control them" and "EXILEEEEEEE"). I don't always, or even often, agree with what measures the Wardens can take: but we'll need them for the next two blights, and sending them off does not look like it goes anywhere good.
Also, Hawke just seems so done. One could argue that Loghain is old and not going to last much longer, but he still would have a few years to make the wardens not be idiots (and I imagine they'll respect him a lot more now that he turned out to be right), and Alistair and Stroud still seem to be doing strong. Hawke, if left, goes off to Weisshaupt. I don't think the Wardens will listen to a non Warden, and they may just kill her for releasing Corphy (who could not have escaped without her (or, well, Carver or Bethany)). That would be bad.
The only big issue is if she's romancing Anders. Isabella is mature enough that I trust her to be able to continue on (she'll be heartbroken, but she's probably the most well adjusted of the LI's by the end of the game), but the other four? Ack. Seb, Merill, and Fenris are not known for making smart decisions, and I wouldn't put it beyond them to come storming at the Inquisition with all their resources in fury. Anders, though, I think is the only one who could end up harming others besides the Inquisition in his heartbreak, though, as he does not have full control of himself. So, uh... Hawke with Anders generally gets to live, with the sad ending of the Warden's exiled. Otherwise, she (or in the rare case, he) dies, and the warden's continue on.