Just thinking laterally, maybe get a small pedal board, velcro on the Sansamp and an Ashdown Ant (or some type of small power amp eg mini Sumo). You can just bring the pedal board and bypass the power amp if no rig is required, or plug the lot into your BF cab if you need a backline?
https://www.andertons.co.uk/bass-dept/bass-guitar-pedals/bass-overdrive-pedals/ashdown-the-ant-pedalboard-bass-amp