Checking and Storing an Empty Suitcase?

Did you ask the hotel?

I've never done this, but here's what KEF offers on its website. Looks like you can rent a locker for up to 30 days at the airport, from a separate company. I didn't try to figure out the price in USD.

Wouldn't seem worthwhile to me unless I were staying awhile in Iceland instead of just connecting flights. Are you?

A reminder that some European airports no longer have storage lockers. Terrorism precaution.

Check information for storage options at the airport.

As Trotter has suggested, some hotels will hold your luggage, especially since you’ll be staying there before going to Spain & then again the night before you fly home.

It’s definitely with a try, enjoy your trip!

When is your trip? I haven't done the storage idea but stayed at the Aurora upon arrival and before departure from/to the US and traveled in the reverse, from the south of Spain to Iceland, in August about 5 years ago. I agree about asking the hotel- it is wonderful and the staff so efficient and friendly- but maybe the size of what you propose could be a factor, vs a set policy they may have.
That's why I asked about the season. I was SO poorly prepared for August in Iceland! I had a cashmere sweater and light rain jacket in the bottom of my carry on that I had hauled around in 100 F heat in southern Spain- as I walked around Reykyavik it was spitting rain sideways from the harbor and just freezing. I was a little more fortunate on my day tour but it was still really cold. If you are also going in summer you might be okay with just a mid-weight parka and warmish shoes- in other words, it could smush into a medium-size duffle if you find a storage option- caveat on the kind of activities you have planned.
I returned to Iceland only for tone day plus transit (Aurora Hotel again) this past July and having a mid-weight parka with hood (or hat) and gloves was perfect for walking around the area. I was able to roll it into a lumpy ball in my personal item.

The only way you will know is to ask at the hotel.

I've stayed at the Aurora a few times but I've never had them store luggage.

Hi all that’s for the replies!

I haven’t asked the hotel yet, and definitely was concerned about the locker doors to 9-11.

We have 10 nights in Iceland, June 9-19

Boon voyage, i definitely appreciate your feedback on your experience there because I get cold easy! Trying to travel light, but the diversity of climates is to be considered.

Why not a foldable travel duffel bag? They aren't expensive and fold into a very compact size when not in use.

Or buy one when you are there.

While I have not left luggage, I have packed a foldable duffle or my old Rick Steves soft side backpack, then on the way home check that with soft durable items, freeing up my carry on bag for breakables. Taking a packable bag then filling it with jackets and clothes and boots would work, once you find a place to stash it. But agree with others, talk to your hotel.

OP…. Regarding trying to stay warm….have you researched Merino Wool base layers? Unsure if there’s an REI near you but it’s where I got mine.

Of course these days you can buy on line. Not inexpensive but so comfy. Will help you fend off the cold.

Happy Travels.