nrfl2041, WIFI, bluetooth, xbee, zwave, other wireless communications
Nrf24l01 with mesh or star setup is the best sollution for you. Other modules are expensive. Also bluetooth doesnt support over 7 nodes.  you can solder 8cm wire to nrf modules to get better signal and increse range. Alternatively you can use "nodemcu". Xbee-zigbee has hibernate function to increse battery life. You can apply enable-disable technique to improve the battery life but it is not preffered beacause of network performance. it is diffucult to assign addresses, setup network topology, and establish routing tablet for every hibernation period. You can choose cheaeper zigbee modules like microchips mrf24j40ma.