Tall gold stands with gorgeous florals will create visual interest across the large open room while not obstructing guests views across the table. It may be nice to have half the arrangements tall and half low.
I think bringing the dusty blue in with linens rather than in the flowers themselves would be ideal. If CMHOF doesn't have suitable linens I would be happy to price some out for you from a different supplier.
A pergola over the Sweetheart table would create a lovely intimate space. Arrangements would dot the length of the table with greenery and pops of flowers winding through the pergola.
We can include either hanging candles or if that's an issue we can string mini twinkle lights throughout the greenery.
The colors would span from ivory to rust, featuring some autumnal oranges, and silvery greens to play up the dusty blue of the linens. I would love to incorporate some autumn fruits with yellow/orange/brown hues, such as Bosc pears and pomegranate and persimmons.