Good thorough question & good illustrations; that was too cold for them, but they appear a bit dry, especially the less foliated one, and appear could use a Sparing amount of nutrient. Could be soil drainage too, if there isnt some gravel or something below the soil. The nutrient may help lot a to reduce the dropping.
Whether 3 to 4 cm of gravel in the bottom, the soil might be bit shallow: maybe could gently raise them up & add 4 to 5 cm soil beneath whats already there. If theyre on dishes then can know when theres enough water when it starts draining into the dish, and after a few hours they may draw some back up as needed.
They look pretty healthy, so maybe wouldnt trim them any more; and leaves will grow a bit to adjust catch more sun (phototropic). They might be two slightly different varieties, could explain some of the appearance differences. Havent ever been a big fan of pruning peppers, they grow the way they grow naturally & lots of their energy goes into the outward growth, which also produces well!
Really might want to right away give them some more soil & a bit of appropriate nutrient & there ought to be good time for them to thrive & produce fruit! Maybe need a bit of pollination activity too, to help the flowers set. Adequate watering without ever really drying out and temperature consistency help too.!