Hi Janrein.
As you likely know there is a sponsored wind powered vehicle race that does race upwind. It's Aeolus race and his held in the Netherlands on a (somewhat) yearly basis.
The current record for directly upwind is ~0.64 windspeed and we're pretty sure that with the propeller switched out for a set of turbine blades would be able to exceed the speed of the wind upwind as well. The student vehicles in the Aeolus race are governed by design requirements that we are not bound by.
From an aerodynamic drag standpoint, 3x downwind and 1x upwind are the same and since the Blackbird has demonstrated greater than 3x, our confidence is high that the Blackbird could own both records.
We're hoping to perhaps get a new set of students at our University interested in the upwind record and do that next year.
You nailed the technicals of the device by the way -- kudos.
JB