Some years ago a study was done looking at the the use of a single fuel being used in the FIs. This was mainly looking at the HRS at Hillcove and Fox Bay.
Taking into account of the heating for the accommodation and running the 2 L/R it was judged that using Avtur in the vehicles would only take about 20K miles from the expected life of the engines. The generator would be negligible for it's life span.