I have been running 35's for about 12 months now, ( 2000 3L Di 283,000 km ) it runs perfectly fine, you do loose a bit of power but its only really noticable in the rough stuff when 4low is not quite low enough A set of reduction gears are next on the list.
my wagon never has much weight onboard other than a couple of swags and tent for the mrs and kite surfing gear and sometimes towing a 500kg boat ( max ) ,
I am not sure how the 3L would go on 35's with a load of drawers a weeks food and water and two tonne van behind........ but I wouldnt be doing that with this engine on any size tyre anyway. Plenty of people do without problem but IMO this engine is too small to tow reliably..... so in short in my experience if you dont need to tow anything heavy the 3L will easily push 35's