If terrain is mostly flat and your antenna is somehow elevated you should be good. If you have more friends in neighborhood it will help as every radio relays messages in mesh by default. Ideal setup would be to have base station at home (terminal) and a handheld device connected to your mobile phone. So 2 devices per person. This way it’s more reliable. If you have HAM license you can use higher power device like this G1 https://meshtastic.org/docs/hardware/devices/station-g1/ The only thing is that you can’t legally use encryption with higher power transmission. In my experience the reliability of this setup varies. It works when users actively maintain and check Meshtastic app. If you have less technical users or users that just want things to work all the time, it may not be the best solution. I found sometimes radios disconnect from Bluetooth, specially when charging. Radio works but Bluetooth connection isn’t established. If you send message it will be received by radio and ACK’ed but person will not get it until connects to Meshtastic app and reestablish Bluetooth connection. Messages are visible on radio if they have display and are not in relay mode. This means that you don’t know for sure if message was read. For day to day use in normal urban setting I find it little finicky and not reliable enough. You have to carry additional device with you and antenna needs to be in good position. Some radios have built in antennas optimized for on body carry. This is just my experience and it will vary on people and situation. There is Nano explorer radio with dedicated notification bell that could be useful https://meshtastic.org/docs/hardware/devices/Nano%20Series/

This solution works best if you don’t have cellphone network reception and all users are actively checking status of their radios (charge, messages, connection to app). This fits perfect with recreational outdoor activities in remote areas. Search and rescue is very niche and unless you engage in such activities on regular basis it’s not something you need. It can also serve as a backup solution for emergencies (neighborhood watch/ prepping).

If you also considering Wi-Fi/intranet solution I recommend looking into Mikrotik wireless wire products. There is more equipment cost involved and it’s completely different use case as it’s stationary solution. https://mikrotik.com/products/group/60-ghz-products