Most of the backcountry explorers we know take advantage of the fact that they're driving a vehicle and can carry lots of (heavy) equipment. Everything needed to make extended forays into the outback, including the kitchen sink, is packed in, on, and around their vehicles. That's fine for them.
I like to travel light.
In the mid-1960s, I learned to pack my old Kelty pack (built by Dick Kelty in his garage) as I prepared for the first of many weeklong sojourns hiking the John Muir Trail in California's Sierra Nevada. That pack had to be lightweight. Even in the '60s, there were lightweight products available for backpacking. A Sierra Cup performed duty as both a cup and a plate. A small mountaineering stove allowed cooking, even when a fire couldn't be had. Freeze-dried food was lightweight and nutritious and could be rehydrated using water from the many clear Sierra streams (giardia didn't worry us then). One cooking pot acted as pan, pot, and secure carrying space in the pack. Fishing with a backpacking rod and reel supplied fresh fish.
For sleeping, only a wimp would use a tent. A down mummy bag on a ground cloth with a jacket as a pillow worked fine, even when the alpine mountain temperatures dropped to single digits. I first used the then-brand-new Space Blanket for a ground cloth before graduating to the much lighter and easier-to-pack aluminized Mylar Space Rescue Blanket. The Rescue Blanket was noisy when the wind blew and when moving around on it, but it was almost weightless and kept the sleeping bag protected from ground moisture. A nylon breathable poncho kept the rain off while hiking and sleeping at night.
That gear, carried on my back almost a half century ago, was a great place to start when planning what to carry in my backcountry-exploring vehicle.
There will be a few exceptions to the lightweight rule. A 12-volt fridge will be in the vehicle. Confining mummy bags work well on the trail, but there's more room in a vehicle, so a nice big square Cabela's sleeping bag will be tapped for use. I must now be a wimp because I'd like to get a rooftop, or some other tent. A water filter will be carried, as well as extra water, gasoline, and tools. Overall, though, the overriding factor that decides equipment choices will be lightweight packability, as if a backpacking trip is planned.
If a pickup is the base exploring vehicle, all this can be easily carried. If I use my Jeep YJ or JK two-door, some deletions or substitutions will have to be made. While I'm not planning on rock crawling with the vehicle when exploring, there will be times when all of its 4x4 ability will be required. The Colorado pickup is locked up front and rear, runs 33-inch tires, and has a winch. It's narrower than a JK and fits on most trails. Its long wheelbase limits breakover and is a negative, as is its low frame height.
The YJ and JK Wranglers are both capable rigs, built with lockers front and rear, top-quality suspensions, and equipment that make them both competent trail Jeeps. The YJ has the spare tire where the rear seat used to be, so it has very little cargo room. The JK has some space when the rear seat is removed. Our EvaKool and ARB fridges both take a lot of the cargo room in the back of either Jeep. Backpacking equipment will be the way to go if a Jeep is picked, unless a backcountry-style trailer is utilized. Even if a trailer is chosen, I'm still going with the "light is better" idea.
There's no reason to weigh our vehicles down until they're similar to overburdened pack mules wheezing up the slightest grade. There's plenty of lightweight gear available. One issue that needs to be considered is that many companies that manufacture these products are actively fighting our access to existing roads and trails on public land. I won't be supporting them. Still, it will be fun picking lightweight equipment from the companies that support public land access for all.
I'll keep you in the loop and let you know what kind of gear is chosen and if it works or doesn't work.