In terms of speed yes…
If you wanted to maintain the same speed with a much higher CDA (drag) then you’d need to output more power and burn more calories which is less efficient.
But to maintain power, no.
Your CDA isn’t going to effect your power production efficiency (except for where you might be in a compromised position but for the purposes of this it’s a moot point).
That’s awesome 
I must be missing something. Just looking at an outside ride I did this morning (power meter and hr).
The calories reported in Trainerroad v Strava/Garmin connect are wildly different. TR is approx. 2x higher.
Strava is showing calculated HR calories there instead of KJs burnt. If you have long periods of consistent power output but a Z1 or Z2 HR you’re going to see high KJs and low HR Calories. The opposite is also true, if you do a lot of intensity that gets your HR up but you’re doing 30/30s or sprint work you’ll see a really high estimated HR Calories but lower KJs
