I'm wondering, if I take it slow, how extreme a situation can I put my low wheelbase, normal caravan, through, while being towed by a 4wd vehicle?

Zero. Blacktop or graded dirt road only. You will do a lot of damage to underneath and shake the fittings to bits.

Most quality built vans should be able to go anywhere a family sedan can go, but not 4 X 4 terrain.
ozjohn.

TA
What brand of van do you have.
Nearly all the coromals have the same suspension setup as their off road models

We go anywhere that you would take a 2WD, but with care. It took us 2 hrs to do 35 klm at one stage but no damage. The off road van that over took us was still fixing his van when we arrived.
Neil

I agree with John, but if you need to take it where there are corrugations, then drop the tyre pressure in the van and EASY does it, then re-inflate your tyres when you can (do not drive at speed with underinflated tyres),

It's a Coromal Aussie Low Line

Thirsty as,
I agree with the others that you can do some "dirt" or "Corrugated" road with with a normal van.
Back in the 70's, the Eyre Highway still had about 300 mile of dirt between Ceduna and the WA Border and I and a lot of other people successfully towed Vans across, The bottom line for this type of road, is the same for all drivers, whether towing or not, "drive to suit the road".
With the independant suspension of the Coromal, at the risk of upsetting some people, I feel it will fair better, because there is no Solid axle to transfer the bumps. I have towed both types on the bitumen and on dirt and I prefer the independant suspension (from my personal experience), especially on narrow bitumen roads. When you have to put one wheel on the shoulder on the dirt and have the other on smooth bitumen, I have found the independant to behave better.
Cheers,

It's not bad roads that break vans, it's bad drivers. You should check first to see if there are any creek crossings where you will ground the body of the van give them a miss.

When driving solo on rough roads you can drive at a speed where the vehicle skips over the top and you can get a smooth ride. This speed will not suit your van as the suspension characteristics are different. If you have instrumentation to measure the ride of the van (wife with hand held CB ) you can find out what the sweet speed of the van is. At this speed you will be very uncomfortable in the tug. You have to drop down to a slower speed, perhaps walking pace to get through the rough stuff. Watch the trees as well

I wouldn't have any fears about poking along a bit of a track to a nice camp spot, provided there wasn't anything to damage the undercariage.

I wouldn't travel at speed offroad however!