I don't want to derail the thread further, as I think it in general would be better suited for a "prepper" thread- but let me preface it by saying if time, money, and space is not a constraint, build all the Faraday cages and EM shielding you can! Have at it, I'm not here to tell you what to do.
Without going down the rabbit hole, I think if you want multiple redundancies, I would strongly be considering those redundancies in regards to plans for food, water, shelter, arms, etc. Just throwing an example out, but rather than relying on a set of solar panels and a spare electric water pump that *hopefully* would survive an EMP, I think I'd rather have plans for multiple alternatives- water purification/filtration, rainwater collection, manual pumps, etc.
Anyways, as I said, I won't derail this further with non-EMP hardening talk. My point was mostly that everyone should try to be reasonable/realistic in expectations. Not sure I'd spend time and effort building my underground basement bunker while living in a 10-year floodplain. Would love to take it to a general prepping thread, though.