"I thought the general wisdom was to keep left of the wall? I was planning on going down to Cowper's Cross anyway, as this seems to be the official route (being more of an LDW event)?

It was all frozen solid on Tuesday which doesn't half make life easier:"

There is discussion about the Cowper's Cross route above and it's drier and about the same time. I may well do it this year. You used to go down the left of the wall, but the Landowner complained.
My fastest ever time at this was a year when it was frozen solid - like a road race! Don't think I'll ever manage 3 1/2 hrs again.
Good luck and hope to see you.