The dowside of hosting your conference in exquisitly beautifull old locations is that they have no airco.

While well managed traditional cooling management can keep them pleasant enough, this would require light programme adaptations, basically shifting to starting early morning - noon, covering the glass dome, and night ventilation, but that seems to be more insurmountable than cancelling.

Apparently the LSE does have airco spaces, but these aren't as inspirationally nice it seems.