If we're lucky/early we get the 22:33, often the 23:11 which gets to St.P at 00:38. I guess your location-based head start works wonders. We usually get the second or third train away from Falmer.
Can I hold your hand on the way? Me and my missus tend to reach St.Pancras about 00:45... despite mirroring your journey route and method. Either that or I'm still so drunk I've really got no idea what time I get back. :wrong: