I landed a glider at Braemar once. I paced the field out while waiting for the retrieve. 180 metres on the diagonal, approach over a stream and a low fence. This was the BEST field I could find after a somewhat traumatic flight involving an electrical failure in cloud. I was later told by the locals it was the only useable field for 30km. I don't think I could have done it in a light aircraft, with or without the engine running. I suspect a ditching could be less life threatening than engine failure in the Cairngorms....
YMMV