This site is a good place to go to get a "snapshot" of Es in Europe. I think there is also a page on Es in the USA and Canada.
See https://www.tvcomm.co.uk/g7izu/radio-propagation-maps/europe-sporadic-e/
Simple QRP projects, 10m, 8m, 6m, 4m, FT8, 160m, WSPR, LF/MF, sub-9kHz, nanowaves and other random stuff, some not related to amateur radio.
See https://www.tvcomm.co.uk/g7izu/radio-propagation-maps/europe-sporadic-e/
In the past I have used magnetic loop antennas with QRP. Although the RF voltage can be very high in magnetic loops, requiring special high ...