Hi John Cross, sorry for the late reply, but I hadn't been here for a while!
There are several thousand Byzantine Catholics in Portugal, with the vast, vast majority hailing from Ukraine. The ukrainian diaspora tends to be well spread out, but they have chaplains who serve them from North to South. They use mainly borrowed Latin churches (as do the Orthodox). The Lisbon chapel has daily divine liturgies, as does Fátima and probably Porto. Other places have weekly or regular services. The main chaplain, Fr. Ivan Hudz, told me recently that the community would like to construct their own byz-style church, but there are no immediate plans.
The ukrainian priests also minister to smaller scattered communities of Romanian, Bulgarian and even some Georgian Catholics, according to Fr. Hudz.
Currently there are only two properly byz-style chapels in Portugal. The Domus Pacis chapel in Fátima, still used frequently by the Ukrainian community, and a small chapel which was built by the exiled Queen of Bulgaria and, after her death, moved to the grounds of the Bulgarian embassy. It is lovely, I have visited it, but difficult to reach, obviously...
The Domus Pacis chapel, as I said, still functions, although the Blue Army, which runs it, has been going through some tough times, from what I hear.
Hope this answers your questions!
All the best,