I'd probably recommend temporarily deleting at least 5 characters (Probably the ones you plan to keep, unless they are currently in a Guild), which will allow you to log back into the 5 remaining, then go and claim anything you want to save from those characters.

Once you have everything of worth removed, you can set those to be deleted, and then open a Support Ticket and specify that you would like your original 5 characters restored.

The alternative, would be still temporarily deleting at least 5 character, but then logging in and adding 5 Additional Character Slot Vouchers, then requesting our Support restore the 5 characters you had to delete to log in.