As has been stated, there is a risk doing just about anything.
The important thing is to always (or nearly always) have a way out.
So, I'd fly into known icing, with the objective being to climb on top, provided that the 0C level was well above (say 2000ft above) the MSA.
I've happily flown straight over the Swiss/Italian Alps, about 2000ft above the highest peak for miles around, and 99% of the time there was a way out - down below are valleys with fields, and there are many other places. But I wouldn't fly in the canyons like so many mountail flyers do - that carries a different danger which needs excellent local knowledge.
I've done 2+ hr flights over water - again there is a way out because one carries a raft, an EPIRB, wears a life jacket, and other stuff.
All the above have a way out - or nearly all the time.
Unlike many, I wouldn't fly at night - though I've had to as part of the JAA NQ and then lots more for the FAA PPL. But I don't think I will do it again. Unless it was a full moon and I was over a very calm sea, or very open countryside. I just don't think one has a good way out at night.
I am also not happy over a lot of forest. That's a near certain death. Oddly, most people think nothing of it.
A BRS chute would be great.