...how would you like it to be handled, honestly?
For example, my own hoped for scenario - perhaps Clementine is a more independent character in the new game, a new member of the season's group (two members of which found her from the hill scene) who helps defend against walkers but does not form the same parent-child bond with the PC as before (so as not to make her bond with Lee seem not special.) You can befriend her, but more like Lilly or Ben did than like Lee did. She is shaped by your previous actions, either acting aloof towards the others (if you told her not to trust them) or being kind to them. But she shoots walkers just as well as other group members, leading the group to respect her and treat her like an adult.
Then in one scene, your character could find one of Clem's drawings. Maybe it could be a picture of Lee and her, or Lee handcuffed in the jewelry store, or Lee, Kenny, Christa, and Omid. Either way, it'd be a subtle reference without all-out continuation of the previous game. And maybe eventually we could run into Christa/Omid, Molly, Lilly, etc (maybe even Kenny, if he's alive) and the whole Lee situation could come up and be explained.
Eh, I guess this is kind of a lame topic for discussion, but I wondered.