Can't comment on the countryman, for the pathfinder, our limit is dictated by weight rather than where to pack it.
The key figures (MRO and MTPLM) should be available for the countryman
The new pathfinders have an MRO of 840kg and an MTPLM of 1000kg. Which means there is only 160kg for user payload. After adding a leisure battery, awning, 2 gas bottles, waste/water containers, kitchen crockery and other odds and ends (plus motormovers) that was it for us. Still spare room, but would exceed weight limit.
General guidance on packing is keep the weight over the axle, but you are more limited in a folding camper. We put the awning in the seat lockers, waste/water bottles in the space in the middle, and folding chairs/tables between the fridge and the wardrobe. With the gas and other stuff in the front locker we get a nose weight of about 65kg, which is spot on for us.
So checking the noseweight is probably the most important thing after deciding on how to pack. I just built a wooden post (the height of our cars towbar) and put in on some bathroom scales to measure ours. Don't need a fancy tool for that.
When we had a Pullman ... we took out the sliding cupboard which took up a lot of centre gangway space when traveling ... and filled it with other things: extra fridge, inflatable kayaks, folding wardrobes, chairs etc.
Keeping the heavier stuff near/over the axle ...
Worked very well and achieved a good towing balance.
When we had our Countryman we had chairs and the shelf unit in the middle space where the table goes, porta Potti right hand side in front of the cupboard, water and waste on left hand side along with a couple of side tables. All curtains, towels, toiletries etc in cupboards ( ours was a 2015 model ) had to leave the area in front of the fridge clear as one of the handles needs to drop in front of it when folding beds in, hope all that makes sense 🤔then of course awning, poles and groundsheet on top before putting the cover on. Had pillows in space under seats but bedding in the car 😊
We put inside: awning, poles, ground pegs, ground sheet, curtains, middle inner tent (in the seats), crockery, loo rolls, kitchen rolls, saucepans etc (in the cupboards), step, 3 duvulays and portaloo (in the gangway), table, chairs, waste and water containers (on the 'roof' under the tarp). The sleeping pods and most of the camper curtains stay attached.
We have the aquaroll on the right in front of cupboard, an oil filled heater on the left, pillows in the space behind the table, shelf unit and rugs plus a duvalay sleeping bag in the middle. Beds stay made up. The awning, poles, and a few other bits travel on top of trailer under the cover. Gas bottles, pegs etc in front locker. The dishes and pans etc stay in a box in the kitchen cupboard, I use non slip stuff on the cupboard shelf to stop anything moving around. Cushions and curtains go in the cupboard inside the door.
------------- Linda
2017
May - 3 nights Yeatheridge.
May - 5 nights Mill Park, Ilfracombe
July - 6 nights not sure where yet
August - 2 weeks Croatia, Camp Lanterna.
2018
May - 3 night Yeatheridge campsite
May half term - 6 nights Cornwall
July - 1 week Cotswolds
August - 2 weeks Vendee.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.