I think he'll find him, but I think Yeonjo will not be living his best life when he does. In fact, I think he'll be working as a slave. I think this because he got dressed in the dead slave's clothes and because in the season 2 preview Yeonjo is shown to be limping. I read that it was a common thing in the Korea of that time period for slave owners to damage one foot or leg of their young and healthy slaves to prevent them from running too fast and escape. So my theory is that Yeonjo didn't follow up on Moonwon's suggestion to fake being a lady widow grieving at a temple and instead was grabbed by a slaver and sold or put to work as a slave. And that's why I think Yeonjo will willingly return with Heeryang when he finds him. But of course, once back with Heeryang, he'll keep feeling like shit about his feelings for Heeryang so, as the preview shows, he'll get into drinking. This is my wild theory
I’m assuming he gonna find him but he's gonna watch him from afar, that's what I hope he’s gonna do