Your 3 years is actually 4 with next year's contrat year. Year 4, IMO, with Demidov having played his ELC and inked to a new, long term contract, Hutson and Reinbacher rounding into peak shape, Suzuki, Caufield and Slafkovsky either entering their prime or nearing it, plus Laine playing in his contract year, we get one good crack at going far into the playoffs with Dobes and Fowler in net.
After that, Laine will be 31 to start his next contract. If he stayed healthy and produced throughout the 3-year contract, he should be able to sign a 6-year deal at good, but reasonable money, or a 4-year deal at top dollar somewhere, but maybe not in Montreal.