I am officially lost at how you can get the bear without doing SW. Anyway.
I would set up the event (give any of the officers a shout and they will be happy to put it on the calendar) and see what the interest is like. Try to avoid a raid night, unless it's after raiding time. If it looks doable, then do as has been suggested and hit SW first.
One thing I do have to ask is - why is using a rogue being suggested ? I thought that the guild summon did not work within enemy cities. If that is the case, then you need to sort out a warlock and someone else (as has always been the way). If not, then great. Go with the rogue