We also stayed in the LM section recently, in mid-late August, and the walk from our room (building 7) to the main area (dining, shopping, buses) is a bit of a stretch of the legs. But, you're staying at a place where you expect to be walking quite a bit, so many folks are confused about what the fuss is all about.
In the morning, heading from your room to grab a drink at the soda fountain in Landscape of Flavors, or grab a souvenier from the gift shop, or catch the bus to the Magic kingdom, the walk isn't so bad. You'll pass other happy vacationers, you'll smile at one another; you might even say "hi" or "good morning!" And then, you'll go on to enjoy a magical Disney Day!
At the end of the day, as you get off that bus which was standing room only, with a couple crying babies, a husband and wife arguing with each other right next to you, and that "oh, so sweet" smell of too many people who don't know what deodorant is, you're about to retrace your foot steps from this morning.
This time, the walk BACK to the room isn't so much fun. You'll be walking alot slower, and somehow, this walk seems to be a whole lot longer than it was this morning!
My advice: prepare yourselves. The tip about driving over to a parking spot near the bus depot is an excellent one. Since we only did the Disney buses a couple times before opting to drive ourselves to the parks each day, we cut the walk back to the LM section by quite a bit. However, we did leave our Disney refillable mugs in our minivan, so we could refill prior to calling it a night. This strategy worked out well for us, and made our Little Mermaid stay a much less taxing one!
Have fun!