Never been above FL410 on the route (service ceiling of type) but strongest winds are usually around FL390 and don't really change a whole lot up to 410 on the "average" day. By "average" I mean fall / winter / spring without any weird double-hooks in the jetstream or such, just a basic meandering westerly windfield with a jet core here and there between 80 and 120 knots. G-V guys may be able to give some better answers.
Have flown average 5-8 monthly round-trip crossings on those route for the last few years.