Cabinets aren't always fully equipped with cards at day one, it is therefore possible that only a new card is required to add extra capacity. Unfortunately there is no way of telling if this in the case in your cabinet.
Google bonded adsl for info on multiple lines.
It does say that ADSL multicast is available, so you should be able to get some extra channels, but I am not sure how many, as there would only be enough for a single stream.
Perhaps someone else may know that?
This thread may give a clue https://community.bt.com/t5/BT-Sport-on-the-Box/How-good-is-BT-Sport-on-ADSL-Multicast/td-p/1384561
The whole thing is a shambles. Allegedly Openreach have a waiting list but I guess it is up to the individual ISPs (BT being just one) as to whether they place any orders on that waiting list or not. If that is the case, the ISPs that don't use the waiting list will never get any slots until the list empties. Perhaps one of the mods can give a definitive answer.
Thanks all for posting. I’m happy to clear this up. We will accept the order which is then sent to Openreach to fulfil. If there is a delay due to capacity issue then the order will go on to a waiting list until a space is available at which point it will move to appointment and then completion.
If there is a fibre order in place and an ADSL order is then placed in the meantime it will cancel the fibre order. Once the ADSL broadband is connected the customer can reorder the fibre but that order will be placed back in the queue for installation.
So if a customer wants service, they will need to order ADSL first. Once that has been activated, then they need to place an order for fibre right away, instead of waiting to see if the cabinet availability changes.
That would put them on the waiting list.
Does what @DavidM has said, help you to progress your home move?