Long range isn't automatically the advantage to close range. Circumstance determines who has the upper hand, we automatically assume that the match is starting in Temari's range of speciality so we give her the advantage. However, if we start her off in Hinata's range, we can assume Temari isn't as strong a taijutsu fighter as Hinata so she gets upperhand in that case. That what I have to say concerning range difference and advantage/disadvantage.
I believe Temari would win though. I just see her as an overall stronger fighter then Hinata. Temari has good enough means to keep out of Hinata's range of fighting, so that itself would be Temari's defense, however, Hinata doesn't have the means of defending against Temari's wind jutsu so that puts her in the underdog position, so Temari ftw.