Also, IIRC, Sportsbet does process BTC withdrawal before free of charge, I'm wondering if they are still doing the same now.
I didn't find any update on whether they still provide free withdrawal fee during the increase in transaction fee. Many sites make change and they may still adjust their fee if they are too high.
I regularly use sportsbet and can confirm that they still cover the fees until now, their sister site bitcasino also doesn't charge fees.
However, that would drop from time to time so probably a $3 fee is still fine and will be confirm in less than 24 hours.
Sometimes you could get away with a $1 fee, I remember few days ago the recommended fee from electrum was hovering somewhere at 15-20 sats/vB.