You still have more than enough time to use at least one ogcd ability while under the effect of Wanderer. The only thing that really changes is that you do hell of allot more aoe damage and you can't move as freely. If you're used landing that 2.5 second Stone III, before an aoe goes off you'll have lots of breathing room. The proc.d version of straight shot is also instant, so you can save that a little to move.