I've been travelling this continent for 30 years... 20 of those in a Defender 110. Everything you need for two fits easily in the back behind the seats, including swags. With back seat passengers, bags can go in the back and the swags can go on the roof rack. I've never understood why people take so much stuff! Less is more out bush IMO.
...it would all depend on how the Jimny rides on the highway for long distance journeys IMO.

