I am looking for advice here. I have to store a number of stringed instruments for a couple, or more years. These include two Fender Am Dlx basses that were built in the last two years, with thick poly finishes, including on the maple finger boards. An old, (1967 Kapa) bass, in (I think) poly. A Gibson SG guitar, with the faded nitro finish, (which is a thin non-gloss nitro finish). A MIM Strat, an Ibanez Artcore, and a few other cheaper instruments, including an acoustic guitar. These instruments will be stored in an insulated semi-trailer in Wisconsin. I expect the temperature to range form mid-nineties, to below zero. I thought I would place a large desiccant bag in each case, and wrap the case tightly in plastic film, and packing tape. Should I leave them tuned to pitch, or tuned down a little? Should I be worried about doing this? Any advice would be appreciated. Thanks.