Mobile coverage in Madagascar's remote regions can be very limited or non-existent, even with an eSIM, as infrastructure is sparse outside major towns.
While major cities like Antananarivo, Toamasina, and Fianarantsoa, along with popular tourist hubs and main transportation routes, generally offer reliable connectivity from local providers such as Telma, Orange, and Airtel, this changes significantly in more isolated areas. The challenging terrain and vastness of Madagascar mean that venturing into truly remote locations, including some national parks and very rural villages, will likely result in intermittent or no signal at all.
Your eSIM will automatically connect to the strongest available major network in Madagascar. However, its effectiveness is entirely dependent on the existing local mobile infrastructure. For critical communication needs in deeply remote areas, it's wise to plan for potential communication blackouts or consider alternative solutions like satellite communication.