Quarkonium production in proton-nucleus collisions is a powerful tool to disentangle cold nuclear matter effects. A model based on coherent energy loss is able to explain the available quarkonium suppression data in a broad range of rapidities, from fixed-target to collider energies, suggesting coherent energy loss in cold nuclear matter to be the dominant effect in quarkonium suppression in p-A collisions. This could be further tested in a high-energy fixed-target experiment using a proton or nucleus beam. The nuclear modification factors of J/ψ and Υ as a function of rapidity are computed in p-A collisions at s=114.6 GeV, and in p-Pb and Pb-Pb collisions at s=72 GeV. These center-of-mass energies correspond to the collision on fixed-targ...