There are a few of us who could brave the wild and have done it; complainers need not apply.
As for nuke preps. Potassium Iodide is just the start. Radiation poisoning happens because the radiation can piggy-back on certain vitamins/minerals/elements and thus, get absorbed into the body. By making sure your nutritional gas tank is full up so to speak, you can minimize the effect. It is the concept behind taking KI.
I would have to go back and look at my notes as to which does what but, we keep on hand N-acetyl, L-Tyrosine, melatonin, Alpha Lipoic Acid, Calcium, amongst others.
Regarding the Mississippi, firmly planted on the west side as recommended by JWR.
Extra supply of diesel stored, Four runners, Dirt bikes, UTV and horses also an option.
One location for if the prevailing winds are from the North, east or west, another safe location if the winds are from due N, E, W or S. Most (NE, SW, NW, SE) probably good on the second from any direction really due to remoteness. Could be in a "safe zone" within 15 to travel between and not have to cross through a hot zone. Bug out bag, animals, and go. Supplies enough at both locations.