Dreams about icebergs can symbolize feelings of being trapped or isolated, as well as underlying emotions or issues that are not immediately visible. In your dream, being stuck on an iceberg may represent a situation in your waking life where you feel stuck or unable to move forward.
The fact that your family members are involved—your parents and your grandmother—suggests that this dream might relate to family dynamics or concerns about their well-being. Your grandmother drifting away could symbolize a fear of losing connection with her or feeling helpless in a situation involving her.
Consider reflecting on your relationships with your family members. Are there unresolved issues or feelings of distance that need to be addressed? This dream could be your subconscious urging you to communicate or reconnect with family members, especially those you may feel are slipping away from you emotionally or physically.
To gain further insight, think about any recent events or emotions that may have triggered this dream, and consider how you might bridge any gaps in your family relationships.