The Argentina eSIM works across Patagonian towns including El Calafate, Ushuaia, El Chaltén, Bariloche, and Puerto Madryn on Movistar's 4G network, with reliable coverage along main highways like Ruta 40. Inside the national parks themselves — Los Glaciares, Tierra del Fuego, Nahuel Huapi — signal drops sharply away from visitor centers and main access points; this is true for every Argentine carrier, not specific to Movistar. Download offline Google Maps for Ruta 40 and the park boundaries before you head out, and budget for dead zones on long bus segments.