I think it really depends, on how well it was initially built, what adhesive was used, etc.
I'm in the middle of doing something similar. My DHE
Manor house was built around 20 years ago and I'm currently pulling it apart. Some bits are much easier than others. Pulling out the windows and doors was easy enough. As mentioned above, if you apply some heat, maybe with a hairdryer, use a thin palette knife or metal spatula, and gently work it around the edges until the glue softens and you can probably tease them out. Because the MDF
is quite 'soft' on the surface, you can get a bit of skinning, but most of it is easier covered up/repaired with some sanding and paint.
Dismantling the house carcass itself is probably going to be a bit harder, particularly as its recently constructed and the adhesive bond is still quite strong. I think a lot of these houses are purposely designed so that even if they're not well glued, they will still hold together. I originally wanted to pull mine completely apart as there's been a little bit of warping, and a couple of rooms are not out of square. In the end though, I decided not to, as it didn't seem worth the time, especially coupled with the risk of doing damage that wouldn't be so easily remedied.
If heat doesn't work in softening the glue, you can look at using a solvent. If it's been glued with something like PVA, it should be dissolvable in acetone. That said I would only go down that route if you're familiar with working with solvents.
I would say take as much apart as you can, unscrew hinges, see if you can get windows, doors, stairs etc. out (as it's Montgomery Hall you can probably still replace anything you might break if you're not happy with how it repairs). Then look at where you are with the house as is left and decide what is worth the trouble.