Interesting Thread
I currently fly 737 lowco/charter airline in Europe, and we are always suggested to do tankering if there a slight fuel price difference at destination.
However I'm not a big fan of this practice, because we always land close to MLAW. Neither very efficient nor eco friendly if you end up doing holding patern at destination to burn the extra fuel.
Another issue is with wings full of fuel at temperature well below zero, you'll be surprise to see ice building on the wings. Common practice is to left fuel on the center tank and refuel the main tanks with warm fuel at destination, it usually take care of the icing pb.