Yeah it is somewhere in there. No one knows for certain. Every Lostmyth or Rails or any of the all time greats don't know. They are probably more knowledgable than me, but Everyone knows it is between 2 and 2.67 I'd say, and beyond that, you can analyze battes, search forums for vets opinions or just go with 2.33 and say, screw it, I am pretty freaking close here, and that is good enough for me.
I personally have gone with the latter. I use 2.33:1 , which pretty much means HV until you hit 360 miles. If you think its more like 2.5:1, then use CV's at 210+ miles.
Really there is only 1 strategic question here, and that is what to use between 200 and 350 miles. 0-200 is HV 360+ is CV.
If you want to be even more dodgy about it, just use 50:50 in that gap and you'll do fine.