Depends on how well compensated holiday overtime is. There are some employees happy to work overtime if their hourly pay is doubled or tripled. However there also those who wouldnt do that for any price.
It broke, which was a major problem, this meant that senior management were being phoned (ho), and relatively high middle managers were on site to deal with the fall out. Of course most suppliers were also closed so everything was harder to fix.
There's good reasons not to do changes when places are closed, or at least skeletoned, for 2 weeks.