We had the same problem the OP did -- the whole prep and then the whole unpack was very time consuming. We developed several very elaborate checklists -- one for clothing, one for recreational equipment, one for medications and toiletries. One for prepping the trailer and the truck. One for food to buy. One for preparing the house for "hibernations" while we are gone (watering, mail, newspapers, etc.).
We then divided up the responsibilities for specific parts of each list.
We then prioritized the lists -- first, prep the trailer and the truck. Next, pack the non-perishables. All in a logical sequence.
When we come home, we have an unpacking sequence with corresponding lists -- first, the stuff that has to come in as soon as we get home (medications and books). Next, the food -- we put the contents of the fridge into empty baskets and carry them in.
We make organized piles of the boxes to be unpacked in the living room and then tackle them one at a time.
The lists are maintained on my computer -- we update and tweak each list as needed. We print the lists for each trip. I am sure this sounds ridiculous -- but we go on about ten major trips a year, so this whole process has to be systematized.
Not everyone would need such an elaborate series of lists, but some folks (like the OP) might find it helpful!