Kerala is the trip for groups that want to slow down. A houseboat on the Alleppey backwaters, tea estates around Munnar, and beaches at Varkala and Kovalam — the state is compact enough that a week covers hills, water and coast without a single punishing travel day.
A full houseboat with two or three bedrooms is designed for a group and works out cheaper per person than most hotels. Food is cooked on board and the boat anchors for the night, so plan it as an evening-to-morning stay rather than a day cruise. Book the boat itself, not a seat — sharing with strangers defeats the point.
Kochi for a day, Munnar for two, Thekkady for one, Alleppey for the houseboat night, then Varkala to finish. One booked vehicle for the entire loop saves a lot of coordination and costs less than the individual legs.
September to March is the reliable window. The monsoon is beautiful and cheap but hill roads get slippery and backwater cruises are often cut short. Ayurveda packages and Kathakali shows need advance booking for a full group, and Munnar homestays fill up over long weekends.