Gen 2, the expansion pack sequel.
I kid, but Gen 2 was more like Gen 1 with extras than a true sequel, fixing some of the major flaws but not shaking up the core formula too much either.
You can see that in how it handled the type additions: dragon got one new member (Kingdra), ghost got one too (Misdreavus), and ice being semi-rare got two new lines: Piloswine and Sneasel (and Smoochum but who cares?) Feel I'm forgetting somebody though, who could it be?
Nope, haven't the foggiest idea.
Steel type showed up this generation, but none of the steel types really had any moves to exploit on the ice crowd. Fighting also got shafted again, as while a few 'mons got some minor toys (Machamp gets the inaccurate Cross Chop to use) the type as a whole has yet to really make a presence. Meanwhile fire still has a mixed job handling ice-types as most still pack coverage moves.
The only real new threat to ice is Tyranitar, which being the pseudo legendary that stands to reason. Oh but wait, base 60 speed means it can only outrun Piloswine and tie with Lapras. Bummer man.
As for the late-commer syndrome, this generation probably cemented the ice route placement right after the 6th or 7th gym. Yet despite this, Lapras is still available after gym 4 (provided you backtrack on a Friday), so there are some options. Still don't see why it takes forever to get Seel or Shellder though, it's not like the Whirl Islands were that special that we had to wait on them.
Want to draw a special mention of hail, because at this point while underwhelming compared to rain or sun it still was a better weather than sandstorm, since it at least made Blizzard 100% accurate while Sandstorm carries no passive benefits to rock types at this point.
So Gen 2 introduces some new threats, but still the ice type is looking pretty healthy. Will it hold out for another generation?