Sorry, thought I answered that the first time.

Yes, a 72 hour kit is enough. The storm is passed and the threat is not immediate. If they need to relocate(no longer an evacuation) to find supplies, now's their chance. Staying put if no supplies are being brought to them and a way out is accessible seems unrealistic.

The 72 hour kit is meant to get you through the critical period during the actual disaster event, and give emergency response enough time to get to you, if they are the only option, or to allow you to get someplace after the event is over where you can get aid or help yourself.