Don't have an 825 but do have an 815. I've been looking to upgrade so we can have a shower we can actually use, but it's hard to beat the storage in the 815, especially after some storage adding mods I've done.
From looking at the floor plan and pictures on Lance website, I think I would look at the below to get more space.
Remove the microwave/convection oven which will double your overhead kitchen cupboard. Or leave it in place and use it for storage.
Check behind the radio and see how much space you can gain there. On my 815, I added enough storage for a few boxes of cracker by opening up the space behind the tank monitor.
Push the bed to one side and then add a matress height storage cabinet beside the bed. May be possible to add two smaller cabinets with the bed centered.
Think I would also open up the access panel below the fridge and see what is there. In that little cabinet below the fridge in the 815, I made the opening larger then added in a pull out pantry plus a little other storage.
