Engine misfires and slow down flashes

Depends. Are both banks running okay, or is one shut down? If both banks are running, then it should be safe to do so, as long as you don't actually have an overheating cat, that is glowing orange.

90% of the time it is simply a failed cat ECU for the right or left catalyst. Once in a while it can be a bad thermoprobe to the catalyst. The last few % it is actually an overheating catalyst from some ignition or other problem upstream.

Update: I reread your post and you say the first sympton was a misfire...not good. So you could indeed have a problem that could contribute to an overheated catalyst. I would take the safer route and flat bed it to the shop.