I have an Isadora who gets Dora and it's a beautiful name on her, suits her to a tee and everyone who knows her has fallen in love with the name. I've had a few "Dora the explorer" comments but tbh who cares, and who even watches it?? (Far too American).
My vote is for Theodora just because it lends itself to Dora better IMO and I'm totally biased :)