Waco is a bit over 100 miles from me and would be a potential destination for me in an emergency. It'll probably be massively slammed though if all of DFW needs to evacuate for some reason. Austin is then over 200mi.
Oklahoma City is a bit over 200 miles if I needed to go to the city the next state over. Shreveport is just under 200mi.
If something is making me leave DFW then 50mi isn't going to get me anywhere. That's not even going across the metro area.
What event do you have in mind that very badly affects your location but not those cities, and you don't realize driving there is a good idea until a day or two after the event?
The 2021 Texas ice storm and related power outages would have been one where driving to Oklahoma City or Shreveport would have been a place to go to. That also would have significantly reduced that theoretical 230ish mile range of a Lightning or similar EV.
Lake Dallas dam breaking after major flooding in the Trinity River would cause quite a bit of destruction in DFW and potentially make things pretty unlivable around here and force a lot of people out of here and into the surrounding areas. Also an event that wouldn't necessarily be seen days ahead of time.
I grew up in South Houston, so I had a number of times of hurricanes coming through and not necessarily destroying my house but making the surrounding areas pretty unlivable for days to weeks. Maybe it gets cleaned up enough in a couple of days, maybe it doesn't.
Oklahoma City is a bit over 200 miles if I needed to go to the city the next state over. Shreveport is just under 200mi.
If something is making me leave DFW then 50mi isn't going to get me anywhere. That's not even going across the metro area.