Ugh, I did a very stupid thing. While in Meridia's temple, I entered the last area and told Cicero to wait just inside, not wanting him to just go charging in as usual and ruin my chance of a stealth shot. Well, I cleared the area and took Dawnguard, not realizing Cicero hadn't come with me until much later and after I had finished many quests. (I suppose I had grown sick of him and subconsiously was glad I didn't have to listen to that Horker joke for a while) Well, I went to the sancuary and didn't see him, and so paniced and ran back to the temple only to find out he is currently stuck inside the locked door that requires a key. I can just imagine him dancing and singing that stupid lute song in there at my misery.

Long story short, is there any way of getting him out without reloading my previous save? I've done a lot of work that I really would rather not do over again.