I'm new here, only joined today and woke to the news that 02 was down and I had not even swapped my SIM over!!
I checked their outage map and it's only parts of the country
I'm in Somerset and seemingly not affected, in fact I have a 4G strength signal constantly, more than can be said for BT, E service or no service all day or night
So, Giffgaff/02 all good so far