Oh, I measured my feet according to the wall and book method, they are both 29.2mm. Therefore I presume I must use 29.5mm boots? So 29.2 x 100 as far as I can tell, within the margin of error of my tools.
Also some extra information:
I live in mainland China, that's why my piste is 'icy' and has probably max 600m vert drop resorts in Hebei province. However I will probably also ski in Korea and Japan at some time. Korea can be icy like China (dry and snow machines and -10 to -20c average in January). Japan though is much softer and more natural and warmer, and is a definite maybe, but cost is a factor. My best friend is from Britain as I am and skis in the alps in Switzerland and France (usually a mont Blanc resort) so that's always a possible. Then again I have family in Whistler BC also in Alberta and in more in Boulder CO, and Telluride, Vail etc etc are all on my bucket list too!
So a lot of potential locations....