"Most elbow to elbow" can be interpreted as a phrase that describes a tight and congested space. The antonyms for this phrase can vary depending on the context. If we are talking about a busy and crowded place, such as a city street or a concert venue, the antonyms could be "spacious", "open", "widely spread out", or "empty". However, if we are talking about a group of people who are standing closely together, the antonyms could be "spaced out", "separate", "spread apart", or "divided". Overall, it is important to consider the context in which the phrase is being used to determine the most appropriate antonyms.