It is not possible to guarantee the uninterrupted running of your system once the upgrade has been applied, so unless you have already made provisions for the change, we strongly advise that you allow Pythagoras to review the upgrade for you in a controlled manner ahead of the enforced process.
Our recommendation is that we perform the upgrade to assess the impact on your system and offer any remedial activity that is necessary and possible in the time frame. This will allow your users to get familiar with the new interface before the enforced date. This activity will represent between 3 and 5 days of chargeable effort, depending on existing system configuration.
For more information, please review the Microsoft FAQ and Checklist.