The sets might be tricky to do sometimes- as I wrote them with film more in mind- but all the scenes where they are walking down main street can be done just along the lip of stage at the front, with the curtains closed. This way sets behind can be changed. Heres an idea: One house set: should have a table, for the Malk family to eat around, and a bed to the side for Bear that first night, and Oscar one morning.
The attic scenes can be down with curtains closed, and just some big boxes surronding him- they're get the idea.
One restaurant: for the bar scenes, and the restaurant scene, and the small soda scene.
You need one park set with a small bridge- for the pooh sticks scene, and the picnic.
One classroom: obviously. When Pepper and group are sent outside, discreetly close curtains and have them enter from other side. Same with being sent to the principal.
You'll need a fence, for that scene, too.
