Last year9which i will repeat this year) I bought new quality packaged socks for everyone(we are the boring white tube sock family) and I bought packaged new undies for everyone. One new one for each day. We were already familar with the brands, so not worried about fit and such.
Then, each person wore their pants on the flight down (can always change at the hotel) and then packed shorts and tshirts and one long sleeve. We had the BCV so washers were in our room, so i packed half of our 9 day stay..so like 4-5 shorts/shirts per person.
the goal was to fit each kids stuff in their pull along back pack, and we had one big suitcase which fit inside it a smaller suitcase. This contained meds and adult clothes. the goal was to not have much luggage ..like no more than what each person could carry, and the extra suitcase inside the other was for the souvenirs for the trip back.
This worked out very well for our family of 5. The new socks and such ensured comfort during our trip and a good excuse to replenish supplies.
So, in answer to your question, you are just there 5 days..pack only what you can carry, if you use it up, then take the time to wash. packing all that extra stuff is only making things more like work for you.