Ice fall climbing in early-mid December

It depends on where you are located and what grades you are looking at.

If you are located in Reykjavík then Múlafjall is always a solid option. In Múlafjall there are all levels of difficulty and also some top anchors in case you want to do some top roping (Gísli, Eiríkur & Helgi)
https://www.isalp.is/wp-content/uploads/2017/12/M%C3%BAlafjall-Siggi-Tommi.pdf

Múlafjall

For early-mid December conditions it’s really just going to be 50/50 chance if you’ll find ice or not. It’s been 10°C and raining for almost 10 days or so, so if early December is going to work it needs to get colder soon.