Plusnet have explicitly said they won't provide a stop-gap for the OP. That may or may not be due to it being a FTTP priority area.
However, according to the Openreach FTTP Fibre Priority Exchange programme web page If FTTP is not available at the premises, then the stop sell will not be applied and any available product can be ordered.
It may be the intention that FTTP is available at the OP's premises, but since 4 months have passed and still no progress has been made it is fairly clear that FTTP is not available. That just requires a database update, and then FTTC could be ordered.
Any work that involves cutting trees is likely to take a significant amount of time. There are lots of regulations that can apply to trees depending whether there are TPOs, forestry, or impact on wildlife (bats and nesting birds). Since the work hasn't happened yet, I expect it will take months (just checking which regulations may apply will take weeks). Installing FTTP ASAP isn't the same as providing broadband in the near future.
To me it looks as if the only way to provide broadband in reasonable time is to reinstate FTTC.
