@Brummumm - there may be a mini sale - just a few days long - end of September or thereabouts. The next main sale will be December, (usually starts the evening of last post before Xmas).
However, Toast’s recent summer and winter sales have been relatively poor and with much less stock than previously. They have also tended not to put much of the previous season’s stock in the next sale recently. (Goodness knows what they have been doing with the last season’s stock - Toast is very weird!)
For example: Summer sale 22 had well over 900 reduced items in womenswear at the start, including the most recent season’s stock. Plus they kept restocking and adding items. By contrast, in 2024 both summer and winter sales had far fewer items, very little restocking and no adding of further items after day one.
This is my long-winded way of saying not to hold your breath for a particular dress going in the sale 😹
Having said that, Bryn is a popular model with lots of patterns, so I would expect at least one of the colour ways in the winter sale, (if not the next mini).