Question about the selection process. Does a larger max group size affect your chances of being selected? Meaning if your application is selected, will they see if any date of the 15 is available for your max group size, then max group size - 1, then max group size - n, etc. until they find a date? If so, that would mean having a smaller max group size would make it more likely your first date choice would be selected as you wouldn't need as many spots when they try for your first date choice?
I'm assuming here they check each of the 15 dates for your max group size first and then check each date for max group size - n, etc. Not check your first date choice for any possible group size in your range, then second date for any possible groups size, etc. If they did the latter, you would be more likely to get a 1 person group on your first date choice than a 7 person group on your second date choice even if it was available!