As 800 says, this discussion can go on for ever, and most opinions will be correct or close to it.
I don't think it is a single/twin engine issue as it is an IFR/NVFR issue.
I also recon it's a Pilot issue, is he/she trained, current and capable to conduct the flight.
The issue of how much training, what kind of training, who does it, how often do you do it and of course, minimum equipment to do the job has to be taken into account. Again, here in Aussie it is only a matter of time before the insurance companies step in and say "we won't insure you off shore in an aircraft that doesn't meet the following minums".
Then they will dictate what we will be flying.
With unlimited money and time we have no accidents or incidents, in the real world where money isn't plentiful, we do it in a single with one a/h, one Pilot and only when the sun is shinning. I suppose it's just what you can afford and good luck..........................