Do you think if I propose to her at a sporting event with 40,000 people that will lessen or increase her odds of saying yes?

50/50 chance I suppose - you could make her say yes then have her back out at the last minute - or in the car on your way home - or you can make a complete fool out of yourself if she says no

If your girlfriend needs parades and grand festivals to accept you then she isn't the right woman for you

Increase.

But then it private she'll decline.

[i][c=#BF0080]Well you know her better than us 👀[/c][/i]