I imagine their argument would be that they travelled here last year, which is fair enough. They could do more to facilitate of course, but don't think it's something that should be expected of them

Didn't they want to come here last year though? The interest in your game at Penrith was pretty much nil, with them getting their lowest crowd in years (which included a couple of thousand Saints fans), so I think they were quite happy to let Wigan sort everything out. The reasons the WCC games are played over here aren't because they want to do UK clubs a favour, they just can't be bothered trying to drum up enough interest to make it worth their while.

If Wigan win on Saturday, I think it's far more sensible to expect a side with no league games before Vegas to come over here and then go to Vegas, then it is to expect a side to play a Challenge cup tie, a league game, go to Australia, then go to Vegas and then come back and crack on with their league campaign a few days later. Thinking back, the NRL also spread their Round 1 fixtures over 2 weeks, so the teams playing in Vegas are the first 4 teams to play and then they don't have a game for 2 weeks. The expectation should absolutely be on Penrith to travel and make the fixture happen if it comes down to a repeat of last year but it won't be.