Deep Freeze

You send a blost of deep cold at a creature, dealing 4d8 cold damage to it and encasing it in ice. An encased creature is grappled and takes an extra 2d8 cold damage at the start of each of its turns it remains encased. If the target of this spell makes a successful Constitution saving throw, it takes half the damage and none of the extra damage and is not encased in ice, but the ice that clings to its body reduces its speed by 15 feet (to a minimum of speed of 5 feet) until it takes an action to remove the ice. 

A grappled target can take an action to make a Strength check against your spell save DC, breaking free of the ice on a success. Alternatively, another creature within 5 feet of the target can make a Strength check on its turn, freeing the creature on a success. The ice can also be attacked. It has AC 12, 10 + your spellcastin ability modifier hit points, and is vulnerable to fire damage.

Using a Higher-Level Spell Slot. You can target one additional creature for each slot level above 4th.