Nay - Overkill. Dance fans have got DOI and two lots of DWTS to compensate. Like the present length (three months) and number of contestants, but would like to see talented celebs last a decent number of weeks, which isn't always the case.
Maybe there is a case for a one-off midsummer event with, say, six celebs doing two dances each.
The Beeb tried this with African dancing, which didn't work that well, but with other dances it might.