Lines are quoted from the official notes; buff/nerf tags are auto-classified from the numbers and can be wrong. Covers the 14 most recent Dota 2 patches PatchMeter has fetched.
⇄adjustEldwurm's EddaWinter Wyvern starts the game with Eldwurm's Edda item. After 10 minutes it can be consumed, increasing the current and maximum level of a basic ability by one. Also increases Winter Wyvern's Intelligence by 25% of its base value at the time of consumption
✕removedArctic BurnNo longer has a one debuff per cast restriction on enemy heroes
▼nerfArctic BurnBurn Duration decreased from 5s to 3s
▼nerfArctic BurnMovement Slow decreased from 16/24/32/40% to 15/20/25/30%
⇄adjustCold EmbraceAghanim's Shard reworked
▲buffCold EmbraceDecreases cooldown by 4s. Allied units gain 60% bonus attack damage for 6s when emerging from the icy cocoon
⇄adjustWinter's CurseAttack Speed rescaled from 65 to 50/65/80
▲buffWinter's CurseMaximum Duration rescaled from 4/5.5/7s to 6s
▼nerfWinter's CurseBonus Duration per hero decreased from 2s to 1.5s
⇄adjustWinter's CurseBonus duration per hero can now be applied after the cast if an enemy hero becomes affected
▼nerfTalentsLevel 15 Talent Splinter Blast Shatter Radius decreased from +250 to +175
▼nerfTalentsLevel 20 Talent Arctic Burn Slow decreased from +17% to +15%