We rope drop and stay late with a 3 hour break in the afternoon and 5 days doesn't seem too long at all to me! If it seems like too much try to take long breaks to rejuvenate and take advantage of hotel ammeneties if they have any good ones. Table service restaurants can take up a lot of time and so can staking out spots for parades, fireworks, shows. We recently went for 4.5 days and still didn't go on all the rides though we did go on our faves multiple times. I love Disney though. You have each other to keep things interesting while waiting around in line, etc... I think 5 days is great! When you go they'll either have shorter hours because of lower attendence, or longer hours because of expected higher crowds so it shouldn't matter too much how many days you choose for your dates, though when it is very busy it is very hard to get as many attractions in and you have to stake out show spots much earlier, no matter if they have park hours maxed out. Have a wonderful time! I'm sure you'll love it as there are tons of awesome experiences in (and around) the parks!