The RL Gold Coast Titans are ave 19,946 this season so it would be possible that a winning GC Suns could ave 20 +as there are tens of ex Victorians who live on the Gold Coast who could be lured into following their local AFL team.
Just for context the GC Titans crowds have consisted of:
14,483
12,452
26,563 vs Broncos
46,835 @ Suncorp (for Magic Round)
18,736
10,232
18,335 vs Dolphins
15,363
16,516
20,877 vs New Zealand
The games I didn’t identify are against Melbourne, North Queensland and the NSW teams.
There are still two home games vs Sydney teams to go.
This is an average of 20,039.
Remove the magic round game and the average is 17,062.