I think League in the UK may be pushed to the precipice (or at least closer than Union). There's a number of the big name clubs that are in parlous financial straits already, and they've not had many games in their season so far. It'll also impact their one big TV event in the form of the Challenge Cup. That's the only FTA coverage they get, and I can't see them being able to have the final. Conversely we've already had the RWC, a lot of the 6 Nations, and a number of games on FTA TV already.
Even though their salary cap is far lower than ours is, they struggle to get enough sponsorship/financial backers as it is. They already had Bradford go to the wall a few years back even after the RFL bought the lease from them for Odsal & let them play for a peppercorn rent until they went bust. As a sport they have far less national presence & coverage. I could see a few of the League Championship and maybe even Super League clubs folding.
Ironically, if League does suffer badly, we could see Union as a Professional sport while League becomes an Amateur sport, reversing the 1895 schism!