need the BB up and running as soon as possible after I move in as I work from home.
Under those circumstances, getting a USB dongle (for pretty much any mobile network, with a PAYG option) would seem sensible, just in case you have no broadband for a few days because of a fault (and gives peace of mind if moving home).
At last property (before Openreach replaced the dropwire) I could lose BB and voice calls for up to 5 days at a time, any time it rained (insulation on outside wiring had perished, but automated tester, which I could use from Three dongle, reported a problem with wiring inside my house). Not impossible to happen, and having a reserve if you work from home and need the internet seems a no-brainer.