On the last day, I faced a similar situation to what you're describing: I needed to securely stash some luggables after I'd checked out but well before the RSA thing was done.
I batted my eyes at the concierge: belle femme, pouvez-vous m'aider?, can you assist a poor man who'd rather not lug his gear through the bustling streets of your glittering metropole? Yes, she smiled, yes I can. The concierge put my stuff in a safe and gave me a tag as ID. By evening, long after I was no longer officially a hotel guest, I came back to the counter, presented the tag, got my stuff, retrieved my vehicle and rocketed out of Gotham at unsafe speeds.
You can probably make a comparable arrangement.
Bon chance!
.d.