I'd put the following locations high on the disruption list
* Oxford Circus (Vicc and Bakerloo cross platform, central interchange)
* Camden Town (as you mention, stops all northern line trans)
* Mile End (Stops All Central line and District from the east)
* Earls Court (All district from the west, all wimbledon services,
although piccadilly would still work)
* Baker Street/Circle junction (Stops circle/h&c Edgware Road -
Moorgate or similar, maybe met line too. ERoad doesn't have that much
turnarround ability either.)