Big hike?
Not being funny, but a big water I'd stick with 12ft rods.
Ardleigh and Alton reservoir, 160 and 500 acres respectively, even Nazeing Meads Lagoons, around 65acres, could be some long walks to swims, and 12ft rods do give you better casting range.
Sounds simple, but co-ordinate your barrow and tackle you carry. Do the standard take out non essential stuff that 'I might need one day'.
I use a Carp Porter Porterlite (original), and I can take the gear for 3 days in one trip, and the 12ft rods and bivvy on top of the barrow.