Indeed they are adaptable,
Adults have caused all this and being a grown up adult they can and will sort it all out, and yes they might even both be very upset but for sure one will, but its the child who has known no one else as there mother and father,
Kids can get over it but they never forget, lots of fathers walk away every day from there kids for sure, but some cant
I am not saying you should stay together just for the kids, but you the father or step father should be there for your child,