I think that each option is great. If it were me, I would choose an option which gives me a year or more in an overseas city, so that would narrow the choice to UCL/Paris and TCD/Columbia. In ordinary times, I would choose TCD/Columbia, because I love Dublin and New York, but these are not ordinary times. Right now, I would choose UCL and Paris, because of the political instability of the USA. Columbia has just bent the knee to Trump, academic freedom is being limited, and students might face difficulties (including arrest and deportation) if they express political opinions. France is still a rule of law democracy. The US is on the brink of becoming an authoritarian failing State. So I would choose UCL/Paris.