forget the dress, but I like that idea with the horns for a theatric costume - we know from texts that they used masks and so far we thought of and made fealted ones, but wicker is another theoretical option. just storing the idea here - no proof yet
I think I like this headdress better than your typical conical hat for a witch's costume. The problem with "traditional" things is that they tend to be overdone absolutely to death. Sometimes something different can be a welcome and refreshing change.