It isn't a big deal. You'll loose some gear, but if you thought ahead, you won't loose much data because you've burned it to optical media, and you can use a compass and map. Sure, long range comm is pretty much out, but if you've planned ahead, anyone who would be worried will know you have a plan and your plan has a safety margin in terms of time as to when they can expect you to show up if comms are out.

It is worth planning for becuase while it is a relatively low probability scenario that for someone prepared pretty easily compensated for, it is a serious one. Just like a plague or the old Y2K-bug. What all three of those have in common, other than being less likely to occure than a bad storm or earthquake, once you've prepared for the likely, getting ready for the unlikely doesn't really cost anything more than sitting down with a few sheets of paper and a pencil and thinking about if for a little while.

Now, if you want implausable scenarios, the zombies or an alien invasion. I like alien invasions who do not come in peace and don't care who your leader is. That's just fun think about.