When all the batteries connected parallel will charge with single charger, I would vote against the idea for storage.
Over the years I had few incidents when battery minder malfunction and killed the battery. Then would one battery develop internal short - it will take whole bank with it.
Those things don't happen too often, but suck when they do.
Disconnecting the clamps turn out the best for me.
Car batteries will hold the charge for 6+ months, while golf cart batteries will power after full year with no problem.
So I would hook up a charger just few days or few hours before planned trip.