Bringing this forward:
SEA Wednesday 2130-ish, Monday 2030 Virtually no line at all.
FLL Thursday 1400 - about 30-40 in line. Probably would take 15 mins. max. Monday 1200 30 in line, shrank to 10-15 in line by 1240. Security is quite thorough but efficient.
FLL may be crowded earlier in the morning as cruise pax try to get away.