It is possible to overland without a rooftop tent by using alternative forms of camping gear. Some options include:
1. Ground Tent: This is the traditional camping option. It can be set up anywhere and offers a wide range of sizes, features and designs.
2. Vehicle Sleeping Conversion: Depending on the vehicle, you may be able to utilize the backseat, trunk space, or truck bed for placing a mattress for sleeping. Some people choose this option if they don’t have a lot of gear to carry because it is safest from weather conditions, wildlife, and other safety factors.
3. Hammock: A portable hammock can be set up anywhere, as long as there are trees or other anchor points. They are lightweight, easy to set up, and can be a great option for warmer climates.
4. Bivy sack: A bivy sack is a small, lightweight shelter that covers just the sleeping bag and is good for minimalist camping.
5. Tarp and Groundsheet: A tarp or groundsheet can be used to create a shelter, whether it's pitched over a rope between trees or propped up with sticks.
Ultimately, the best option for you will depend on your personal preferences, the type of trip you're planning, and the climate and terrain you'll be traveling through. Keep in mind that not all the options are suitable for all types of weather, so make sure you're prepared for the conditions you'll encounter on your trip.