With any luck, by the time their grandchildren are pensioners that figure may have reached the magic 100

[Nonverbis]

Upstream Proficiency by Virginia Evans and Jenny Dooley.

Could you tell me whether 'any' is suitable here? I'd say that 'some' is what should be used.

With any luck

 

[emsr2d2]

It's a stock/standard/set phrase. Don't think about it too hard! Just accept that we say "With any luck, ...". You'll occasionally hear "With luck" but not "With some luck".