Last stateside 10m WSPR spot of my 500mW

WA4WW (6969km) was the last stateside station to spot me today at 1622z, quite early, at -22dB S/N. The last USA station spotted on 10m WSPR here was WB1FIG around 20 minutes later. He was also -22dB S/N. As I mentioned before, more power really does not seem to matter much. What is more important is that the path is open e.g to the USA. What I'm saying is running 5W, 50W or even 100W would make little difference if the path is closed and the MUF was not high enough. Maybe a few minutes?