I've actually been thinking along these same lines, and was about to post a similar question. I had a red champagne down in Mexico that I loved and haven't been able to find anything even remotely close stateside. (I do live in Montana, not exactly wine country, so maybe that's no surprise.)
My thoughts along these lines would be to ferment out a relatively fruity blend or varietal kit, as I think that offers a lot to the style. I'm also thinking backsweetening with maybe a can, tops, of grape concentrate to add a bit of sweetness (also something I personally enjoy)...but that presents some challenges to the natural carbonation technique...so I would probably opt to keg the batch. You can backsweeten in bottles if you properly heat pasteurize after Co2 has developed, but I wouldn't think this would be necessary if you don't sweeten the final product, since there would be very little residual sugar remaining after the Co2 sugar was consumed.
I would be curious if anyone's had experience here they could share as I'm rather interested as well.