Are large thyroid nodules (24mm) more likely cancerous?

I have already had my left thyroid out 10 years ago due to a cold atypical nodule pressing on my windpipe. It was determined benign after removal. Now I have a 24 mm cold nodule on my right thyroid. They said they could leave it if is benign because there is extra space on the other side for my trachea to move. ? Are large nodules more likely to be cancerous? Are taking thyroid meds after complete thyroid removal really hard to adjust?