Epoxy would probably be your best choice. Apparently, it can withstand freezing temps without cracking.
Since this bracket would not be under much strain, the clear epoxy should work well.
If you can remove the freezer door and lay it so the area to be repaired is horizontal, then smear the epoxy resin/hardener mix where you need it.
BTW epoxy will not stick to Saran Wrap, so if you need to hold the epoxy in place so it doesn't run, use the plastic wrap as a kind of mold/form (whether a single layer or balled up).Just smooth out the part that's going to touch the epoxy beforehand so you don't imprint any wrinkles. You may want to "practice" first.