Are these running on Sunday? (Technically today)
What times are they, and from/to where?
How much would it cost for either a London-Wherever via Corby return.
Orrrr a North Camp-Wherever via Corby return.
If that makes sense...
If EMT are diverting via Corby then your ticket destinations will need to be as follows:
Northbound - Leicester
Southbound - Kettering
You can easily tell on the timetable if it's diverted via Corby because Kettering - Leicester usually takes 30 mins max, whereas if you're sent via Corby it takes nearer an hour. Also there will be no stop at Market Harborough and there'll be some comment about a bus link from either Kettering or Leicester.
Hope this helps.