Internal size wise they are all similar within their class range. Compared to your current Forester the Outback, previous gen Xtrail, Mitsubishi Outlander, another Forester would all be good. Try also looking at a v6 5 Spd auto Suzuki Grand Vitara or 4 Spd auto 2.5L model as well. If off-road clearance isn’t as important a 2nd gen Honda CRV (hatch side door open) is very roomy on the inside also and better economy than many in its class and the later gens may be worth a look. The Mitsubishi Outlander v6 2nd gen is worth look with very roomy deep cargo floor and best verandah feature unique hatch double tailgate hatch and shelf.
If you would be happy with a future 5 door Suzuki Jimny, then any current medium suv interior would be also, but not as funky.
I had many AWD suvs from 1990s, Suzuki Vitaras and Grand Vitaras both 2 and 4 door, 1st & 2nd gen Toyota RAV, 2nd gen Forester, Nissan Dualis and my current one (getting old and soft) is a compact Nissan Juke AWD with bigger off road tires. With all these cars I have always fitted slightly bigger and AT tires some with lift kits to give them more ability. One main issue with many suvs like Outback and Maxda CX5 and any thing like them is the low overhanging bumper clearance when going off-road which is a serious problem hitting track dips which I have seen people loose and scrape bumpers due to bad approach angle, a lift kit may help. My Nissan Juke hatch though small on the inside, modest 180mm ground clearance with bigger tires has the best bumper approach angle of them all, very powerful 1.6L turbo petrol with best 40mpg Hwy and 36mpg town, much better cvt system, tight compact and fast 8 second 0-100km acceleration.
The latest gen Toyota RAV and hybrid is outselling by twice others at the moment, hybrid has the best economy for medium class category vs other petrols.
Latest Suzuki Vitara AWD 1.4L turbo petrol is worth a look, goes like rocket and good economy but less interior space than others with good reviews.
If tall boxy interior is priority then CRV, Xtrail, Grand Vitara, 2nd gen Outlander are the go; economy then CRV or latest RAV hybrid; off-roading capability then Grand Vitara or Forester.
Given your requirements and older school outlook a Mitsubishi Delica v6 van (18mpg) or Express 2.4L 4WD, except for lower economy, are about the only significant space increase options. There are some other options like older VW Caravelle 4WD camper vans as well getting quite old now.
My favourites out of all those cars I had were 2nd gen forester, 2nd gen RAV4, closely followed by Vitaras for off road ability. Others with lift kits and bigger tire potential would be the Nissan Dualis, Outback, Mitsubishi Outlander v6.