The short version is that the spell is inherently broken. It cannot be made fair as written. It's basically 'Hold Person' with no save, and it just wrecks way too many opponents outright. To fix it without banning it:
a) Fort save negates. It's really important that it be a fortitude save, because dexterity tends to be inversely proportional to constitution. Big creatures with low dexterity get flattened by this spell, and it's low enough level to quicken it, which means a high level caster can simply outright win against virtually all opponents in the game. Hardly any opponent can survive the loss of ~22 dexterity and the resulting immobilization.
b) Any creature with cold resistance or immunity is immune, not just creatures with the cold subtype.
c) Victim receives a new save each round to recover from the effect.
At that point, it's only slightly more problematic than hold person - because cold resistance is still slightly rare than immunity from mind effecting spells. Which means that even toned down that much, you'll still see casters use it frequently. That's how good it is. Personally, since I believe casters are OP even at the standard balance implied by core, I just ban it. To bring it into my game would require all of the above plus increasing the spell level by 1-2 for both the lesser and standard versions.