+1 to Tjin's pertinent question....

Really, keeping your items organized and accessible is probably rather important. Off site storage might be good or it might be bad, depending upon circumstances. Would you want first aid materials stored off site?

For that matter, I am not so sure one can make a rigid distinction between emergency supplies and ordinary "stuff." My pantry is well stocked (has been that way for years) and could sustain me and my family for at least a month without a trip to the grocery store. It's just food, after all.