I've been through several. Including Katrina and Gustav. And a flood. And never needed more than what I usually carry. My zt0550 pretty much covered if. Even during flood rebuild, I carried never much more than a traditional, an improved wharncliff trapper, at the time.
Honestly, a chainsaw was much more useful and needed than a pocketknife.
Self defense always falls to the S&W M&P shield.
To be 100% honest, I don't see the draw "what knife foe xxx". One knife may be better at a particular cutting than another, but they'll all accomplish about any cutting given time and patience. You ain't gonna clear trees off your driveway with any knife or machete (after Gustav, we cut 3 out of my parents house, 4 off their driveway, 1 off my driveway, then 6 off the road just so we could open access to the main road). And if you need a bigger knife to cut firewood to cook (for one example), well, it's all wet anyway and you didn't prepare well. I do keep a ratmandu in the trunk of my car, but it's gonna be bad to need it. Put that preparation thought into something more productive.