Stopping Escalation

Well, you can always do a go-to from whatever activity the update comes in from, but a simple workaround might be to do the same status check in the Escalation Action code. Your escalation will still fire, hence show up in the reports, but if you're not too concerned about the reports, here's what I'm thinking:

You set your escalation as per normal, using whatever wizards you need.
Once this is done, edit your Escalation Action code, add all the generated code inside an if statement which checks if the condition has been met, e.g.

if (myCondition == true)
{
    // Add escalation action code here
}