I have seen reports about people sleeping in their cars for a few hours at the Portal. It will not be a problem.
You cannot carry enough water for the whole hike. The weight would be overwhelming. Refilling is mandatory. Start with two liters each and refill as needed. There are plenty of opportunities to refill all the way to Trail Camp. There is a spring about 1/3 the way up the switchbacks, but it may be frozen in the early morning. The Trail Camp pond is the last guaranteed water. I have filled bottles from creeks and ponds using iodine for purification. Dirt was never an issue.
I would pack an empty third bottle and fill it at Trail Camp so you are carrying 3 liters to the summit. It is a long way there and back to Trail Camp. It is important to drink plenty of water to avoid dehydration and altitude sickness.
Read recent trips reports just before you leave. I believe that the trail is dry and water crossings are not a problem.
Read the weather reports just before you leave. I have been on the summit when it was 65F where shorts and T shirts were fine. I have also been there when it was 40F and the wind was howling. Look at the picture at the trail head where a blizzard came out of nowhere in August. Are you ready for that?
Hope this helps and good luck!
