"Relax." I say this over and over to people who are deciding whether to try to make ice lanterns of any nature--globe, bucket or whatever. Even a total "failure" can be beautiful. If you put out 10 buckets or balloons and they all froze solid - maybe arrange them in a circle or a pile, put a candle in a glass container to protect it from the wind (if needed) and watch the ice light up. It is like the icicle lanterns we used to make as kids when insulation was not as advanced as it is today:
#1 break off as many intact icicles as you can,
#2 arrange them pointed end up in a circle in the snow (tightly or overlapping),
#3 put a candle in a glass jar to protect from snow and wind,
#4 light the candle and watch the light play in those beautiful natural forms!
The same is true of chunks of what you think might be unusable ice. Think laterally. Don't throw away your "rejects". Try and use them another way.
Then, the next time you put out your balloons (or buckets) don't let it freeze for as long, and then you will have what you were aiming for -- an ice lantern where a natural cavity in a form of ice can hold a candle!
So RELAX, a flame captured in ice in any form is beautiful in a dark night.
Contact me with questions or suggestions!