Other factors to consider here as well, with the proviso that, for discussion, a particular pilot is proficient in both types...
If generally flat terrain (Florida, mid-western USA for examples) the single is quite OK, even IFR/night, provided however that the ceiling is reasonable. If the ceiling is below 1000 agl, little opportunity for a forced landing. In this case, the twin is a better bet. Overwater/high mountains etc, most of course would prefer the twin.
Piston engines today, properly maintained, are very reliable, and most accidents in singles are not the result of engine failures.
Turbine singles are very popular now for those that can afford them and although engine reliability is superb, sometimes engine accessories can do you in. Take for example PT-6 powered singles. If the propellor governor pilot shaft breaks, the prop will feather immediately, leaving you with a very expensive glider...with the engine still running. Have had this happen twice on PT-6 powered twins...sure was glad for that second engine.