It's possible without alien set, you just need a team with 4x armor (10plats), anti-freeze, and at least 4x dmg flask. You can also ask other players to help you out.
The only problem is looting the polar backpack, it's rare and as stated above it requires multiple elixirs and you can sometimes fail killing the Toyman and wasting those elixirs instead. Haven't seen anyone looted/wearing it yet.