Speaking of groups/conferences, how about this idea?
For the argument's sake there needs to be 20 NRL teams so for example Wellington, Perth, Brisbane 2 and Central Coast are added to the comp.
Then all the teams are divided up geographically into 5 groups: East, North, South, West and Distant.
East: Central Coast, Sea Eagles, Rabbitohs, Roosters
North: Broncos, Titans, Knights, Brisbane 2
South: Raiders, Sharks, Storm, Dragons
West: Bulldogs, Eels, Panthers, Tigers
Distant: Warriors, Cowboys, Wellington, Perth
Then 1 team from each group is used to form conferences. This ensures that teams in the same geographic area don't play each other twice which allows for increased travel equity. For example:
C1: Cowboys, Central Coast, Broncos, Raiders, Tigers
C2: Warriors, Roosters, Brisbane 2, Dragons, Eels
C3: Perth, Rabbitohs, Titans, Sharks, Panthers
C4: Wellington, Sea Eagles, Knights, Storm, Bulldogs
Notice that each conference has only 3 NSW teams (I know Canberra isn't technically NSW but I'm counting it).
So, each team verses the other teams in their conference twice and each team from the other conferences once. Adding up to 23 games. Plus there could be an extra round added so teams can verse a rival from another conference a second time, such as Dragons v Rabbitohs or Panthers v Eels. Thus adding up to 24 rounds.
I think this method greatly reduces the unfairness of travel. While it can still be unfair for teams like Perth and New Zealand I don't think there is any other way to make it more fair.