A properly maintained small generator (5 kW) will start easily after a couple of months. With a stabilizer in the fuel and a half dozen pulls on its cord, mine started after siting for a year in storage. From there its trickle chargers or maybe even a rapid charger to get cars and trucks running.
EMP won't be a problem for electronics that is powered down when the pulse strikes. Its not the EMP energy itself that breaks down solid state devices, its the normal power source that does the damage after the pulse field exceeds the insulation withstand voltage of solid state junctions. That said, many engine controllers are continuously powered even when the vehicle is turned off to maintain processor state information. Things like cockpit clocks are also hot off the battery and may have to be changed.