Consider our situation in August last year:
DUB-LHR flight delayed. The option to cancel existed, EI offered to put up all the pax at DUB for the night, but pointed out to the pax who insisted on continuing that they would be diverted to LTN.
Baggage was offloaded at LTN. Pax who had to be transferred to LHR were asked to wait for the bus, whereas those who wanted to continue into London on their own were free to do so.
S.