W3CSW (5886km) appears to be the last station in the USA to spot my 500mW 10m WSPR beacon at 1810z. WSPRnet is (currently) working again.
Local G4IKZ (18km) has spotted me several times since. It seems to depend where Nick beams if he copies me or not. Yesterday, Nick did not copy me for hours last night, even though he copied G0LRD running 50mW many times.
UPDATE 1930z: G4IKZ only copying me now, so W3CSW was the last USA station copying me today.