I have a diesel pickup and for hauling a heavy 3400 lb. camper or towing my 9,000 lb. boat and trailer the diesel torque is great. For general use however in the backcountry I would always choose a gas powered vehicle. Many small towns do not have gas stations that pump diesel. I often get fuel when the tank is only half empty as I know I need a full tank to make it to the next fuel stop. You can also forget about going into Mexico with any diesel vehicle made in the past 5 years as it will require ULSD which is not found south of the border. Diesel engines also add weight at the front wheels which is exactly what you do not want for an offroad vehicle.
Dropping the air in the tires on dirt roads is not a good idea. It greatly increases the chances for sidewall damage that takes a tire out permanently. I drop the air pressure when on sand but never on dirt. Better to use a tire that is good for both dirt and pavement. Tires that are good for sand are also generally good for snow as in both situations you want the tires to ride on the surface on not dig down.
I understand about the ride quality or lack thereof with a solid front axle. Having had solid front axle 4WD vehicles including ones from Willys, Dodge, and Toytoa, I welcomed the much better ride with an independent front suspension when it became available with the Toyota trucks and my current full size diesel is a GM as it too has IFS which makes for both a smoother ride off the pavement and a tighter turning radius.
You will have the most flexibility offroad with a 1/2 ton with a popup camper though many people tow a high clearance trailer so they can put toys (snowmobiles, ATV's, etc. in the bed of the truck.
A little harsh dude. Plus, plenty of bad advice.
First off, you can remove emissions equipment that require ULSD on modern trucks provided you have no state smog and $.
Second, I doubt the OP is building a prerunner thats gonna see a lot of time mobbing at ocotillo. Heavy up front is a big concern if you are trying to run waist deep whoops at 60 or getting your truck off the ground across cattle guards. Overland=low speed and vehicle protection.
I think you are incorrect in your assumption that dropping tire pressure offroad is a bad idea. It makes for a smoother ride and better traction. Obviously dont run 7psi on your stock rims, or you might have some failures. But dropping reasonable amounts pressure isn't going to destroy your tires.
And when have you ever seen a wide snow tire for road use? If you are going into the wilderness in snow, sure floatation makes sense. If you are driving on the highway, you DO NOT want to float. You want to cut thru and purchase whatever solid surface is underneath. Same concept as hydroplaning, or skiing. No such thing as narrow water skis, and no such thing as narrow pow skis. But seeing as you live in COASTAL california, I should probably take your advice on how to drive in the snow.
Plus a half ton will guaranteed be over legal weight with a pop up camper/gear/multiple occupants.
And to OP, unless you want to look cooler, or get gnarly off road, your michelins will make a fine tire in snow and ice. We run those on my wifes yukon and they are great tires. Also, I fully endorse your decision to run diesel. Way longer service life, able to carry high loads, and your MPG will be like, double, what you would be getting with a full size gasser and a pop up.