Welcome to the forum!
Phals do tend to prefer slightly warmer temperatures in the day compared to the night, but 68F is not a terrible temperature for a phal. I'm sorry to hear one of the spike's lost its buds (typically called bud blast), but it sounds like the plant itself is healthy if the leaves are a good medium green and firm. If the orchid is completely in moss, be especially careful not to overwater because moss holds water for a very long time, especially with lower temps. Others here recommend the skewer method as a way of testing the medium. If you search Skewer method, you'll find a thread on it. Repotting might be a good idea to check the root system, but if the phal is in a clear pot, check the visible roots and if they look rotten or brown and mushy, a repot and removal of those dead roots will help it out. Good luck, and let us know if you have any other questions.