Are you planning to go completely off-grid, or will you have some cell coverage at camp spots?
The honest answer is that you need both offline maps and a way to call for help - they solve different problems. Download detailed topographic maps on your phone using apps like Maps.me or Gaia GPS before you leave, and bring a physical paper map as backup. That covers navigation. For emergencies though, offline maps won't help if someone gets seriously injured and needs rescue. A satellite communicator like a Garmin inReach or similar device lets you send distress signals and messages even in dead zones, which is genuinely useful if something goes wrong. It's not cheap, but if you're spending days in truly remote territory, it's worth the peace of mind.
Beyond gear, tell someone detailed plans about where you're going and when you expect to check in. Leave them a schedule and contact info for rangers or local authorities in the area. Bring a basic first aid kit and know how to handle common emergencies yourself - sometimes you won't need rescue, you just need to stabilize and wait for the next scheduled check-in. Also keep your phone off most of the trip to preserve battery; you'll want it alive in case you hit an unexpected area with spotty coverage. The satellite device is the real game-changer for remote camping, but it works best when combined with planning and offline resources, not as a replacement for them.