We have had today a gorgeous & sunny winter day, the temperature around - 8 C.
In the morning my ice lantern was ready to be taken out of the buckets.
I used two buckets of different size and put the smaller with a weight inside the bigger one.
Then filled the gap with water and added my overbloomed white hyacinths there.
The freezing took 2 days. I think the lantern needs a couple of candles.
With tulips an ice lantern would look beautiful.