I think my size probably helps my caffeine tolerance. You're what, 20+ kg lighter?
I accidentally took 2g of caffeine instead of 200mg (don't fuck about with caffeine powder, kids!) before a turbo session before going out to dinner and it didn't even appear to impact my sleep.
Shit, I didn't even think of that. Imagine 2x1L bidons filled with 12hr cold brew. Look out PBs! :D