From this site, you know that a super-X solar flare is the most powerful event in our solar system and that it is capable of pushing a Titanic payload of CME toward earth.  The CME can cause a geomagnetic storm on Earth.  There have been a few big geomagnetic storms in 150 years of recordkeeping:

Back in 1853, a British solar astronomer named Richard Carrington was observing sunspots through his telescope when he saw two blinding beads of light cover them.  He rushed to get witnesses.  18 hours later, Earth had auroras all the way to Jamaica and telegraph operators worldwide were getting zapped by their equipment.  CME-induced messages still transmitted over telegraph lines that had been disconnected from their batteries.  This "Carrington Event" is the biggest one on record.  The Carrington Event was estimated at -800nT to -1750 nT (nanoTeslas, measured by magnetometers around the equator.  A regular aurora only registers at -50 nT at the equator)   [18,19]

July 23, 2012, JUST TWO YEARS AGO a superstorm tore through Earth orbit and hit the STEREO-A spacecraft instead of us.  It missed us by a week.  But Daniel Baker, lead on the study "A major solar eruptive event in July 2012" (published in the December 2013 issue of the journal Space Weather), said that it was comparable to the Carrington event.  It was estimated that it would have read at -1200nT at the equator.  [19]

NASA paid for the 2008 National Academy of Sciences study "Severe Space Weather Events--Understanding Societal and Economic Impacts" and their summary of likely damage is dystopian.  The item I found of most concern was the vulnerability of our power grid because of interconnectedness:  350 transformers serving 130 million people were likely to be irreparable and require at least 12 months to build and replace.  Of course, the US vulnerability map doesn't even have Alaska on it.  [21,22] I was on a tour of GVEA's BESS facility last week.  BESS is their warehouse of NiCad batteries that they use as a local backup system.  It carries a large load for 15 minutes until they can power up another generator.  I asked the electrical engineer if GVEA was better prepared for a solar event than most power grids because of their experiences overcoming auroral events.  He said he wasn't aware of any special preparation for induced currents and that the aurora has had no effects on the grid during his tenure.  He said they only have one spare transformer, a small one.  Sigh.   With so many of our electronics more sensitive than they used to be and with so many of our systems relying upon electronics, this bodes ill.

It would appear that...

if we in high latitudes get the pretty lights as a benefit of being under the plasma showerhead, we are also the most vulnerable in a major geomagnetic storm.    With field lines converging here, charged particles fall like rain.