I could see him getting over 100 if all goes right. However, not to be rude to the player or dismissive, but 140 is astronomical. Scoring does not increase linearly with icetime and his game is constructed around scoring goals. He has no where near the playmaking abilities of a player like Henrik Sedin imo, and he managed 110+ season but no where near 140... he also had 83 assists. You might think, "who cares...laine has a much better shot then the Sedins", and you would be right...but then you have to consider this:
What would his stat line have to look like? 75g 65a? I don't think he will ever be a 80-90a type player based on the above, so you're essentially banking on him hitting Brett Hull/selanne single season goal totals... which currently would require him to either become a volume shooter or shoot between 31.5% - 35.7%... probably unlikely for the latter over a full season.
I can see him possibly getting over 100, but 140 is imo a pipe dream. But if you're a peg fan and you like your guy, well I can't hold that against you. I like him too. Like you're whole team actually.... all we have is McDavid
Edit - I guess the point I'm trying to make is that if you look at all of the truly special and historic years. Like Gretzky's 216 and the Mario 199 season, etc... it's guys who put the puck in the net sure, but they all had massive assist totals. Their assist totals were more than players are scoring in total points. That's what it takes to hit the 140-160-180 point range, 2ppg with like 1.5apg....