The lake is great, the roads should be fast and the run is flat. Trouble is you might set a PB that is difficult to beat . I'd give it a go but am already signed up for the Outlaw and I don't think two weeks recovery would be good!
I still hope to pursude her to let me do it, afterall it is a good warm up for IM Wales which co-incidently is 3 or 4 miles from her aunties house which is another event I'm trying to get permission for (though she has about 95% agreed to me doing that now!)
you'll have to hope they provide a wave maker and import some hills to make it like Wales