Neglecting aerodynamic savings due to reduced speed as this is extra math I don't feel like doing...

So at ~140 (Strava) watts I do about 17mph. So here I am at about 3600s*140(j/s)/17mi = 30 kJ/mile. I live in Illinois so I'll neglect my 10'/mile

at 70kg with 1100m of climbing, this is 70(kg)*11000(m)*9.81(n/kg) = 7,500 kJ

so 7500(kJ)/30(kJ/mi) = 250 extra miles probably +20/- 50% cause I have no idea how good Strava watts are, but it should get you in the ballpark.