The current is stronger in the summer and less strong in the winter. Making a winter transit from south to north gives you the advantage of less current as well as higher probability of southerlies. Just make sure you don't end up in a storm out there, there have been a few boats trashed going wide.
We did a run up the coast a few years back, hit 2-3 knots of current but with a 25kt southerly behind us most of the way up it was fine. Except when the guys ahead of us got bombed by a school of flying fish and had one stuck up inside the furling headsail, it had died there by the time they got to Southport and stunk the boat out.