Doctor Who Cosplay - Plan B

No one can ever accuse me of not being prepared. I know UK weather is…changeable. And as it seems to be nodding towards warming up I wanted a back up plan just in case it was boiling hot.

It had to be something to do with 8th doctor that I could sew up at moments notice and accessorize with what I got in the wardrobe already.

It had to be one of the sisters of the flame. Also thought it might be good for photo if I wanted to do something different (although I need to find a goblet).
I already have a shawl bought in preparation and a necklace that looks suitably timelord-ish.
I could go two routes for the dress as you don't see much detail in the gloom.
So either I use -:
1) My regency dress pattern which is a tnt pattern for me. I can whip one up in no time. It would also double up for jane austen festival later in the year and as a summer dress.

I could wear a chemise underneath and make it sleeveless for speed.
2) A modern maxi dress pattern I haven't tried before.
3) Drape a 'roman' dress using the instructions in draping period costumes. (I probably wouldn't need to do any cutting and could un pick and re use the material again later.)

 I rewatched the webisode a few times. I noticed some had a underdress and over tunic...

I also noticed they had a 'V' neck and a waistband. this gives me a basic shape to find.

Which do you think is best?