I have become a fan of long-term storage! I currently have two units in two states (one climate-controlled and one cold/plain storage) and getting ready to rent an add'l climate-controlled storage.
I have stored anything and everything and have never had a problem with anything being stale or musty - esp. in climate control, both in places of extreme climates.
Here are the problems I *did* have:
1. One storage company decided not to plow snow one winter but did not tell anyone. I was living out-of-state at the time and paying a quarter in advance. When I returned in the spring to ship my belongings to my new place, I found my storage in standing water. Bad deal. Almost everything I owned I had to end up hand-washing off a light misty layer of mildew that was a bit like dust. Very light, but existent, nonetheless. I've always been a well-organized person, so I had everything on pallets and covered. Otherwise, it might have been worse - as the building also had a leak, again unreported. I obviously moved from this site and ensured the next site contracted snow removal.
2. One summer, I had an old buffet begin to show a hairline split on one small portion. I had not intended it to be stored through the summer, or I would have contracted climate-controlled storage.
But other than that ... I'd store things again - anytime. It definitely beats the cost of moving things, the hassle of unpacking, then repacking and removing if you decide you don't like where you've moved or if the job didn't turn out as you'd hoped.
I'd suggest moving with as little as possible to wherever you may be going. Just take the bare necessities. You can always pick up a few basics even at a discount store or second-hand store if needed. Mattresses are cheap these days at big box stores like Costco's and Sam's.
Most moves are hectic enough without the whole packing/unpacking process (which I've done many times). Ensure you like the place and your job first, *then* you'll know what stuff you own that you want to even pay to move. Then take a trip "home", visit your old friends/stomping grounds, and move only what you really want.
For the rest - have a weekend sale which you can post in the paper a week or so before you go back or... call a few charitable organizations to come pick up what you don't want. You'll get a tax break at no cost to you to deliver it somewhere, make a few bucks which might even cover storage costs, and end up only paying for and moving what you really want to take.
I always store mattresses and pillows in zip protectors. A few quick bursts of Febreze and a few hours out, and they are good to go! Pillows can be washed and dryed (unless they are down). For clothes and fabrics, I use cedar bricks and balls to keep the moths out and the clothes smelling ... better than moth balls.
Nothing should be ruined, esp. in climate control, unless the building had a leak or other problem as described. Someone is pulling someone's leg - perhaps to earn a bit of a profit? I'd question that.
Clothing can always be washed or dry-cleaned and pressed/steamed if really needed. Same with furniture (steam-cleaned).
I paid $50/month for about 5 years, then one place went up $10/month since they'd never raised prices. No big deal for what it was worth to find those things once I'd arrived. After 5 years, that was still only $3K for what most ppl were reporting paying $15K to move one-way, then another $15K to move back (AK).
In the Midwest, I'm paying $60/10x20/cold storage, month-to-month, long-term. If I wanted to pay 11 months in advance, I'd receive the 12th month at no charge. Climate-control will cost me $50/month/10x10. Same deal - free month with a year's payments upfront. I set it up on auto-charge, so I don't even have to think about it - it's just charged each month.
So... PACNW - $720/year; Midwest will be $1320/year for two units: one cold (old files, glassware, things that won't matter being cold), and one climate-control (antiques, photos/videos/etc., quilts, older books, etc.). And I have the peace of mind that I don't have to pack, box, ship, unbox, sort, wash, organize, ... until I am totally settled where I *know* I want to be long-term. Or... I can spend part of my time in one place I love and know if I want to take a few summer months someplace else, I have all I need there for housekeeping.
I know this is longer, but I'm happy to share whatever might help you in your moving process as someone who moves frequently and has "lived with less" for many years.
Also, instead of renting a place for a year as some folks do - including setting up all your utilties, deposits, etc., you can often negotiate a VERY great monthly rate with extended stay sites which include *all* your utilities without deposits, usually high-speed wireless, cable, local calls if not some LD (and if not - use your cell for this), sometimes breakfast, and housekeeping! All for less than it'd cost to setup temporary housekeeping.
You can send your virtual check for the thousands you'll save to my next moving & storage fund.
You should be able to find some sort of nugget in all this.
If not, DM, and I'll be happy to share any other packing or moving tips.