It was a fairly unusual set of works, in that Ely-Cambridge was closed Saturday but not (or at least wasn't supposed to be!) on Sunday, which is unique in my recollection.
This did make my travelling Nottingham-Ely on Saturday rather tedious - what would normally have been a 1.5 hour journey was instead over 4 hours, not least because the EMR services didn't connect into the XC/GA buses running from Peterborough at all, arriving a few minutes after they left in each case. And then the XC buses were all going via March rather than some running directly to Ely (which they normally do, and indeed were doing on Sunday), which added more time to the bus journey. It seems that EMR really ought to have been running buses to Ely too, in order to have reasonably-timed connections with their trains. Also irritating was that the alternative of going via Leicester and then XC to Peterborough - where the buses did connect fairly well - wasn't an option due to the MML also being closed.
(As an aside, I do wonder how wise it was to have Gloucester, Stockport, Huddersfield, the MML north of Leicester, and most directions out of Ely, all closed on the same weekend).