I did exactly the same thing as I was reading the OP, and was about to post the same reply. Wierd x2

If you're planning on returning often then any place is relatively safe. The Prospector's Shack west of Helgen is a nice location and I think it's abandoned after a dragon attack and it has a chest - just keep returning before it resets.

Aren't the expensive wardrobes safe? If they are, then you could move into the jarl's longhouse of Falkreath. Siddgeir doesn't mind when I sleep in his bed and he has plenty of these expensive wardrobes in the bedroom.

Have you checked to see if there is a mod that adds a house to the Falkreath area?

Seems there are add-in houses for everywhere now.

The absolute best place right near Falkreath is the DB Sanctuary, as far as I know it's the only safe location with all the amenities in one spot. You have to either clear it out or not complete the DB questline to use it though.

I actually haven't noticed: do the tables and all the containers get destroyed?

There is a farm around Falkreath to the North i think, where you kill a couple of vampires. I dont know if its safe in chest and all but its cool!

Yeah, the only thing accessible is a dresser and a wardrobe in Astrid's room. And I'm not 100% certain they're the same dresser and wardrobe as before "the incident" but I'll have to check on a character that hasn't completed the DB questline yet to make sure. Seems to me like it would be easier to just make the wrecked sanctuary a completely different cell though.