Many factors
Many factors needs to be considered:
Water temperature
Swimming skills and physical condition of the occupants
Survival equipment and training
SAR assets in the area
etc
These factors can be used to determine the risk of not reaching the shore following a successful ditching. This risk must be evaluated against the increased risk of performing a ditching with slighty higher airspeed nearer land. I'm not familiar with the helicopter type, but normally is is possible to perform a (slight) turn into wind during the flare. A somewhat higher ROD is no crisis as water is substantially softer than the ground (at the impact speeds we are discussing).