When to go to hospital for natural/unmedicated birth

Hey,

Our plan is to go to the hospital for an unmedicated di-di twin birth.

Our many obgyn's say if baby A is presenting breech at delivery then we will have to have a c-sec. We plan to labour at home as long as possible before heading to the hospital.

My question is when would it be too late to go? At home labouring we won't know if baby A is breech or not last minute, and I'd want to leave enough time for an epidural should the first baby be breech when I get to hospital delivery.