Breakup

Try and stay calm and neutral through this worry

As things stand there is no knowing what will happen

Keep lines of communication with DIL open and positive. keep away from any topic of their relationship so that you have a way to keep in contact whatever happens

You don’t know yet what will happen so try not to worry.
She might decide it’s not so great here in the UK but it’s out of your hands, whatever happens keep a good relationship with her if you can.

I am not sure where you are?

How terribly distressing for you and your son.

It is possible to maintain a relationship at a distance, there are several GN's who have GC living abroad, some in Australia, who through Face Time for example, manage to keep their relationships going.

Of course that will depend on the relationship you have with your d.i.l. and also whether the fact that this little boy's dad being in the country where you are, would enable your d.i.l. to stay.

Your relationship with your d.i.l. is pivotal, GP's who have and maintain a good relationship with their d.i.l.'s are less likely to lose their GC if the marriage breaks down regardless of how close they live to one another.

Try to calm down, you don't yet know if they'll be required to leave, so spend this time solidating your relationship with your d.i.l. and GS.

Hope it works out.