Step #1 in preparing for a 911 outage is to have hard-copies of the non-911 actual phone numbers of the emergency services you might need: especially police, fire, ambulance.

And go ahead and put these emergency numbers in your cell phone - for reference even if there is no cell service.

911 could crash without a disaster event precipitating it.

For the sake of neighbors, it would be good to have multiple copes of the various emergency numbers.

And, of course, always have sufficient fuel in your tank to drive your own vehicle to a hospital if need be.

Does your area have a 411 information number? 411 should also be able to direct a phone call to local police, fire, etc. but not as quickly as 911.