The general consensus (but opinions vary) is to keep your neck under tension at all times, except for maybe when changing strings. I think the only exception to this is if you ever ship your guitar on a plane for any reason. If it gets put with baggage and cargo, the high altitude temperature/pressure drop (only passenger cabin is pressurized) and subsequent return is quite extreme and quick, and supposedly could crack your neck if strings are left tuned.

In your case, just dropping the strings down a bit wouldn't hurt anything, but I doubt it would really help anything either. But also when you do finally pull it out to play it, you run greater risk in breaking the aging strings tuning it back up.