We have a 2012 Forrest River Lexington 283ts which has as almost identical layout and floorplan as the Cambria your looking at.
Due to it's being "downsized" from a traditional class c, the outside storage does suffer. There's really nothing you can do to increase it.
I will tell you that, for us (2 adults) there is adquate storage, and I carry what I want in the way of tools, folding table, grill, lego type leveling blocks, air compressor, hoses, sewer stuff, patio mat, sun blocker screen for the awning, ect.
Folding gravity chairs are hung on a chair holder attached to the back ladder, and you will not be able to carry anything "big and bulky".
We tow a 2013 Subaru Crosstrek with no problem, and the rig drives like a dream (did have to do some upgrades on the suspension).
Any questions you may have, let me know.
Steve & Cheryl + Charlie & Casey, our furry kids.
2012 Forrest River Lexington 283ts
2013 Subaru Crosstrek toad