The immigration issue was not an issue for Esther and Dan because after struggling with all things BREXIT they decided not to run with the issue and stay in the moment instead. It is all on their blog, first how they let themselves get carried away and then how they came to their senses.
If anything, this matter was blown out of proportion by the British press who were obsessed with Brexit at that time anyway and everywhere. The rumour that Esther would have committed suicide because she did not want to lose the life she had, originates in the Brexit mania and it is the nastiest frame in her disappearance as far as I'm concerned, even worse than the old maid's tale that she and Dan had broken up. It is hurtful, it is degrading and it is simply not true. A fabrication of the lowest order.
All IMO.