When I was small, I remember there being a regular children's magazine coming into our hose, and that included a "Bastelbogen" on the center pages (at least some of them did). So you could cut out and glue together a little house, or something else. They'd quite often find their way onto the train scenery that came downstairs from the attic around Christmas time. (I think the scale more or less fit, but frankly I didn't really care. The important thing was that I'd get to cut and fold and glue and then have a little something to put there.)
Later on, I once made a large cardboard castle... which then stood on top of a cupboard for ages, getting a little messed up and dusty and deteriorating a bit over time. These days, I usually pass when given the chance to buy one - I still like the idea very much, and I'd enjoy the making, but then I never know what to do with the models. (I guess one could glue them to the ceiling and make an upside-down landscape there?) In case you also have a liking for those lightweight mini buildings, and don't mind having them stand around then, you might want to take a look at the Schreiber-Bogen website or, to be precise, their English shop. I've linked you straight to the churches, but there's also houses, ships, and whatnot.
Me, I always get a little nostalgic seeing these paper model sheets. One day, though, when I have too much time...
Something that you may find suitable are the model buildings that are intended for Wargamers to decorate their tables with while playing. Pretty standard European domestic buildings of various eras (What, they had wars in Europe?), they have internal bracing which can fold up, allowing the entire model to fold nearly flat so several can be stored in a box somewhere until needed to come out an play their part on the 'World Stage'. There are also Fantasy versions if that's more your thing. Some are .pdf's that you have to print and glue to suitable backing yourself, but you can print as many as you need, others come as pre-printed sheets, so they go together quicker.
Isn't this the happiest thing I've met today! You may guess that one or two will be winging their way here for Christmas, as several of us in this family find model-building fascinating, including paper ones.
Here's an idea for what to do with models, small ones at least: hang them on the Christmas tree, or on a branch stood up somehow with lots twigs for hanging. Many of our ornaments here at home, including a small model church, are of paper stock cut into comes designs, such as snowflakes or deer or Nutcracker ballet characters and either left white or painted. They take little space and can go into a small box, but fulfill the desire to build or design.
Very best and thank you for alerting us to this treasure,
Natalie