Working backwards from move day
The most reliable way to plan the network side of a relocation is to start from the confirmed move date and work backwards, rather than starting from the beginning and hoping everything lines up in time. Carrier lead-in orders, cabling installation and comms room fit-out all have their own timeframes, and some of these can take considerably longer than people expect.
Setting rough dates for site inspection, carrier ordering, cabling completion, and a test day before the actual move gives everyone involved, including the cabling contractor and the internet provider, a shared timeline to work towards rather than a single deadline sprung on them late.