On the subject of Cake, either would be fine with me, which isn't very helpful, but I suspect I'd happily eat both.
As to arrival time, I'm a bit unsure about when to leave, let alone when to arrive.
Various computery things keep on telling me that the travel time to York from home is 4½ hours, but I don't believe this. I have a magic GPS that supposed to know about things like traffic, but I can't use it all the way, since it will only last 3 hours or so on it's battery, and until I do some engineering to the car's electrics, I can't plug it in (there's no cigarette lighter fitted to the car), so I'm planning on keeping a bit of power for the last bit of travel into York (ps I may be looking for a power plug to charge this up before the return journey!)
If I left Croydon at 2pm, and it takes me five hours I'll arrive at 7pm. If it takes me eights hours, I'll arrive at 10pm. On past experience of driving long distances either duration is possible! It's possibly a case of how early can I turn up and not be a nuisance.