Helen Mirren as the Alternative 7th Doctor in Schism.
I think it's possible. Around this time OTL she was done with Blackadder and had done some serious roles. With an ATL Doctor being a woman you could have the Doctor regenerate as a woman due to tachyonic radiation interference or something. And Richardson would make a good Doctor.Is that who you think will become the doctor next
Oh... power play there Doctor.