We've never had a 3,000+ attendance before October. Our largest September league figure by a distance in the 3 seasons since the pandemic was 2,588 against Concord on 23rd September last year. (We've generally had very few home league games in September in recent years.) The August Bank Holiday figure of 2,248 against Cray was almost identical to the last 2 years on the same bank holiday against Chatham and Welling. The FA Cup figure against Leatherhead was a few hundred down on the comparable ties against Haringey and Margate in the same round in the last 2 years. The first midweek and first Saturday league games, against Hendon and Whitehawk respectively, also down on those against Canvey and Hastings last year. These are obviously small sample sizes.
I'd say the greater worry is the risk of losing Saturday home games to opponents' cup runs. Hastings on 12th October and Wingate on 2nd November are both vulnerable to ending up on Tuesday evenings in the winter (when we won't pull much more than 1,000, if that) if those clubs reach the 4th qualifying round and 1st Round respectively. Horsham next week and Billericay on 19th October are our only "guaranteed" Saturday home games before Potters Bar on 9th November. On the other hand, we might end up playing all our home games as scheduled, and replacing trips to Lewes and Folkestone with home FA Trophy ties.