I don't see why he can't get 100% custody with the obvious parental alienation going and if Alice is jailed for period of time in March, he will have to have them then. There are plenty of parents in similar situations to Ioan who have full custody of their children. They find ways to cope. What about the millions of couples, where one them dies suddenly?
I have friend who had a stroke out of the blue in October and it was bad as she wasn't found immediately, she was in a coma for a while and since then she has been a rehab facility. She was the driving force of the family, taking her kids to all the competitions around the USA. Her son is a rising NHL hope in his senior year at school. Her youngest daughter a possible Olympic equestrian, just a year younger than Ella. Immediately her family who live outside the US, came to their aid. Her friends rallied around and made sure that the children's lives continued as best they can in the circumstances. It worked so well, that nobody at the compay where her husband is a senior manager, knew about her illness until recently.
I realize that is not the same as this situation, but Ioan has proved he has a strong circle of friends who he can rely on by having them as chaperones when he has the girls. If he was granted full custody, I could imagine the Judge could agree to Ioan moving them to the UK where he has bigger support circle in his family and more chance of work. With the proviso that he pays for Alice's travel costs and accommodation. Kelly Rutherford is example, that it can work successfully. If Alice is jailed, her visitation would be limited anyway. Bianca has already indicated she enjoyed her time in the UK and got on well with his family. Alice doesn't have any of this. The girls would benefit from being removed from the immediate area where all this trauma has occurred. With therapy, kids can be very resilient.