I have a somewhat similar dilemma, traveling ORD-LHR-MXP in Club World. The only flight combination that gets me to Malpensa at the right time has a 1 hour connection at LHR.
Arrival from ORD and departure to MXP are both in Terminal 5, so the connection time is technically legal.
Presumably I will have to clear both immigration and security before I board to MXP. Is this doable?