"Usually"if the route is only 1 degree different, up or down Lat, the the recaluclation of the ETP is pretty meaningless, otherwise I would contact your dispatcher have them reclalculte a new ETP. It's worth noting that the CFP is nothing more than a plan when you push the power up, after that it becomes very dynamic and can vary significantly as you move along your track. Constant monitoring of you fuel and time scores are a must.