According to what Elliotte Friedman reports, Harris will sign a two-season entry-level contract with Montreal. He will burn the first year of his contract as soon as he plays a game with the CH. This means that he will only have one season left on his contract, which is next year.
The young defenseman's clan here seems to think that he will be able to maximize his value next season in order to sign a big deal. What doesn't work in his favor is that this one contract season will be his rookie season. Unless there is a big surprise, it would be surprising if he manages to prove he is worth much in that short time.
The most likely outcome in this situation would be for the CH to agree to a low value bridge contract. If that contract is for two or even three seasons, the CH will get a lot of money back. Once again, Kent Hughes used his genius to sell the CH to the young Harris.