In the multiferroic Cu2OSeO3 system, the interplay of interatomic exchange and the Dzyaloshinskii-Moriya (DM) interactions leads to the formation of a spin-spiral ground state. An exotic skyrmion-lattice arrangement can be further stabilized by the application of magnetic field. Our recent time-of-flight (TOF) and triple-axis (TAS) neutron spectroscopy experiments revealed a complicated structure of magnetic excitations in Cu2OSeO3, confirming recent theoretical predictions. However, the long pitch of the spin spiral in its zero-field ground state makes high-resolution measurements necessary to resolve individual helimagnon branches. It is impossible with a conventional thermal-neutron spectrometer. Here we propose to employ the cold-neutron time-of-flight spectrometer IN5 with magnet to map out low-energy helimagnon excitations around the (000) wave vector.