Nearly all mainstream caravan manufactures offer a 2-berth model in their range with full kitchen, bathroom and all the luxuries you would expect in the 4/6 berth models.
However, they tend to be heavy as they are made in the same materials as the larger caravans. Therefore most 2 berths are over 1100kg, which means they are too heavy to tow with small cars. For this reason alone, the market tends to be limited, as most small micro caravan customers like to go for that magic 850kg or under option. But if weight isn’t a problem then they are a good alternative to the more cumbersome 4 berth alternatives.