It depends. Remember, it was only in the mid 1980s onwards were concrete efforts made to harden RAF airfields against direct attack and some airfields, such as RAF Leeming, only had NATO funded work completed in the early 1990s. Public infrastructure built between 1960s - 1990s often had defensive/protective measures designed into them; others less so. A lot of CNI - eg water reticulation and the railway network which often dates from the Victorian era - would require effort during TTW to harden them from attack and spares would be dispersed from central stores - firstly to put them closer to the area of need but also to provide a measure of redundancy. British Rail had a network of hardened network control centres across the UK; some of the rather ugly trackside architecture of the 1970s looked that way as it was designed to protect critical switchgear and control facilities. The National Grid had air-gap high speed breaker gear to protect transformers which would survive EMP; not today.
Similarly, quite a few LAs only paid lip-service to preparedness - the rise of Nuclear Free Zones (thanks KGB!) in the 1970s and 1980s saw (Labour) councils dis-invest in passive and civilian defensive measure on the basis that it was 'pointless', but I bet a few bottoms would clench if Naval and Frontal Aviation unit started clashing with NATO forces....
As you know I am interested in national resilience and started a thread in the Current Affairs forum. Surely current anti EMP measures are secret? When you say civil infrastructure was hardened against bomb attack, do you mean nuclear blasts, conventional bombings, or IEDs and attacks by Spetsnaz?
The RAF Support Command Alert Measure saw training helicopters at Shawbury and Valley (Wessex and Gazelles) committed to Home Defence - either in direct support of the forces or to the Civil Authority. IIRC, some Gazelles were to go to RAFG. Dominies were to be used for communications, postal and courier duties. The UAS and AEF aircraft - Chipmunks and Bulldogs - were organised into regional liaison squadrons and flights for communications and surveillance purposes. The Chippies were allocated fall-out monitoring and 'public control' ie monitoring refugee movements.
During the Falklands War, some naval ASW Wessex crews were not needed in an ASW role, so they stripped down the cabs and operated in the commsndo support role.