Circle of snow

Snow, one thing many will agree is the best thing about winter. You and your circle have taken it upon yourselves to ensure that winter celebrations have a certain level of magic to them, lighly dusting snow and hanging holly, berries and mistletoe. Other circles believe that decay is necceary, you believe that some things have their time and other have theirs, to this end you are mainly active in winter. During the rest of the year you ensure that other things have their time to shine.

Snowdrift

You may create an area of difficult terrain made of snow encompassing an area with a radius of 15ft. This terrain lasts for an hour or until you are incapacitated or die. Creating a snowdrift consumes a use of your wild shape. Hostile creatures that start their turn or move through your snowdrift as part of their turn take cold damage equal to your druid level.

Frostbite

You know the cantrip chill touch and always have it prepared. Additionally you are resistant to cold damage. Any difficult terrain composed of snow or ice is treated as regular terrain for you.

Abominable friend

While you have a snowdrift, you may consume a further use of your wildshape to summon a friendly Yeti. This Yeti is under your command and takes its turn immeditely after yours. If the Yeti takes fire damage, it looses its allegiance to you and will attack the nearest creature until it wither runs away or is killed.

Leeching cold

When you do cold damage to a creature you regain a number of hit points equal to your proficiency bonus.

Deadly chill

Any hostile creature within your snowdrift now takes cold damage equal to twice your druid level if it starts its turn in the snowdrift or moves through it as part of its turn. Additionally your snowdrift now encompasses a radius of 20ft.

Apparently 3rd level requires to be included despite not having a circle feature at 3rd level.

You would normally expect an expanded spell list but I didnt want to include one, but to make it work, it requires something at 3rd level because technically at 3rd level theres a class feature that is really an expanded spell list in how it works, but not all circles have it.