If you have a package with the ultimate hopper pass - then yes, doing room only rates on either end is a good deal, esp if you can get discounted room only rates. With your package, you can start using your UHP as soon as you attempt to check in with the package rate until midnight of the last day.
Which means you can check into your 1 night room only rate then the next morning, go to the front deck and attempt to recheck in again keeping the same room. If you can keep your room, all you will have to do is update your room keys to UHP and on you go to the parks. There is a slight chance you might have to switch rooms so prepare for that by not completely unpacking 1st night. Even still, just go get your bags bring to their holding area before going to the parks and check in when you get back. The front desk will still update you to UHP early in the AM before you head out that first day.
Same thing on your last last night. Your last pakage day, ask if you will be able to stay in same room. If not you will need to pack up and hold your bags, go of to the parks still utilizing UHP and then when you return that night, recheck in for your room only rate.
It sounds complicated but I think it is worth it. Why pay for an UHP package and not be able to utilize 2 days of it? If you tell the CM when you are checking in the first night, you want to try to keep the same room for 3 ressies - it may help. Don't accept an upgrade above your package room either unless they say they can keep you there all week.
HTH some