First, congrats on getting a fiberglass trailer!
My wife and I also have a Scamp
5er with the side shower/toilet, but our "standard" Scamp
came with a 4.6 cubic foot 'fridge, located next to the doorway across from the privacy/toilet room. We've made some pretty extensive changes to it that really help -- or, at least, really help us -- use it for extended periods of time.
We also use a lot of fresh ingredients, and found the 4.6 works quite well for extended dry camping
, if you use a pretty simple organizational trick. What we did was get four shoe-box-like storage containers with squared-off sides and use them as refrigerator
drawers. They fit pretty snugly on the bottom shelf, encroaching somewhat into the milk-jug cut out, and fit well on the next shelf up once I'd taken a hot-knife to the plastic to carve out a spot where the drip-tray is at the back of the 'fridge.
This leaves the milk-jug area free for a 1/2 gallon jug of milk, and the top shelf free for stuff that doesn't fit in the drawers, like Celery. We use one drawer for fruit, another for vegetables, one for meats, and the last for dairy and anything else that needs a home. Freezer gets used for meats and frozen vegetables. Works pretty well . . . and the drawers help keep the cold in when you open the door.
The thing about using the closet space next to the door is you loose all that storage space, including all your hang space. If you're already planning to do major modifications, you might consider doing something like our loft re-design.
We took out the "sofa" at the front of the trailer (which really isn't very good at being a sofa), and extended our loft platform so we could have a front-to-back queen-size bed (no crawling over each other when we get in and out of bed) with a chest of drawers, a hang-space closet, and various storage spaces built around the extended platform.
It's a big project, no doubt. If you like the idea and you're up for the challenge, though, I did a write-up on how I did it here