The 2020 update of the European Strategy for Particle Physics called for a technical and financial feasibility study of a "future hadron collider at CERN with a centre-of-mass energy of at least 100 TeV and with an electron-positron Higgs and electroweak factory as a possible first stage". This study started in 2021, and will be completed in 2025. Recently the CERN council held a midterm review of the study, helped by various expert committees. In this talk I report on this review, and on the key points of attention for the remainder of the study.