[m_in_m]

I could see whichever one of the Breakfast presenters of the day simply staying on to do it - Jon Kay, Sally Nugent, Charlie Stayt, Naga Munchetty, Roger Johnson etc etc.

This would make an incredibly long day and reduce flexibility within Breakfast. The presenter could end up doing five hours on air. They'd presumably not be available for the daily programme meeting and have less time to input into the script. 

Even if each presenter only does one day a week the One and extended Breakfast is certainly adding to their hours or taking them away from other activities e.g. pre recorded interviews. 

I'd have thought the One would need its own presenting team which will undoubtedly mean on occasions some travel cost.