They can always 'bite the bullet' and move anywhere if the cost of premises can be afforded but obviously it is more profitable to minimize outgoings.
Regional development grants are an incentive to bring new business to areas of high unemployment or where other businesses have closed down, leaving empty buildings that should be re-used.
Trying not to look nationalistic, the UK is four countries and each has it's own development policies and grant schemes. The north of England isn't the only place to move to, there are closer options in South Wales for instance, 2 hours drive from London/Birmingham and with excellent air, rail and sea connections. I would advise them to look elsewhere, there are probably better options more suited to the workforce while still allowing the expansion they need and without sacrificing connectivity. The M4 corridor in S. Wales for example is full of new, large factory units, has an abundance of trained labor, low costs and undoubtedly can offer a better quality of lifestyle than most of the SE England.
I should point out that I am a local Councillor but on the NW coast of Wales and I have no direct connections with S. Wales or any other UK regions.
Brian.