Are there plans to extend the range of regional variations on Freeview?
No. Because all the satellite channels can be received within the UK, it is possible for the BBC (and ITV too) to make all these available to everyone.
However, on Freeview there is only a limited capacity from each earth-based transmitter. Therefore this limited capacity is used to provide additional channels, including the "correct" ITV and BBC region.
Therefore it will not be feasible for this limited capacity to broadcast other regions.