Like Pianotuna said
not enough battery to carry the minimum load you have calculated
totally impossible for the 400w per hour you might do
lithium does have its advantages, but its not magic and unlimited
a laptop, cellphones tv will not run 1800 wattHrs
where did you get that 200w to 400w per hour number
forget any idea of solar powered electric heat or A/C
limited MW and coffee maker, OK thats doable, but unless your ensconced in an RV park, its LP heat, LP fridge, lp hot water
and some use of the generator during MW use or battery recharge when there is NOT enough sunshine,
because roof space can not hold enough solar, the van can not hold enough battery
for what you described