Thanks.
Based on this condensation data then, pretty sure that unless you have really drained the tank down, then the amount of water present to condense in the sealed system as a fraction of the liquid left, is very small and unlikely to have any affect on .... well anything, unless left outside in a climate that swings and for a very long period of time ?
Therefore faced with the question empty or full for 6 months, then full will win, but really sounds like either is not an issue.
My winter layup is really to work on it over a prolonged period and tick off all the jobs realized from a summer season, so most of it will also be up on stands eg DIY wheel refurb will consume a few w/s' alone
Thanks again everyone