New Scene - New Republic Senate
Create establishing shot using shot of Resistance ships returning to D’Qar. Remove all the ships except troop transport. Have that ship flying toward a new planet. It is a city planet, but clearly not coruscant. Maybe you can see oceans and green earth on the sunny side, but city lights on the night side. Add other planets/moons around it. This is the Hosnian system. Otherwise you could simply have a establishing shot of a new planet, no ship needed.
Maybe you could add some New Republic ships to the space around the planet as well.
Not necessary, but could take an establishing shot of something like future Earth from one of JJ’s Stark Trek films (maybe with some tweaks) to again reestablish that this is not Coruscant.
A little trickier, but here we could take some wide shots of the Senate chamber scenes from the prequels to establish the interior. Unless we shoot new footage, we can use shots of the Trade Federation/Nemoidian delegation and the Malastare representatives from TPM, but redub them to create new dialogue regarding how the New Republic sees the First Order.
Maybe the Nemoidian feel like Leia claiming the First Order has a superweapon is nonsense, that she is a warmonger. Maybe they’re saying, “There is nothing to fear, the First Order is merely a fringe group with little real power”, for example.
Maybe the Malastare delegation wants the Republic to take action, or vice versa. Some reaction shots of Senate pods could show everyone breaking down into arguments, which could be augmented by shouting crowd soundbytes. A quick shot of Kor Sella in a pod might could be made where she is silently watching this breakdown occur. I know there is only a brief, artificial shot of her not speaking in the reinserted scene with Leia, so this might be difficult. Maybe it could just be used as a quick reaction shot between the Nemoidians and the Malastare senators, just to establish she is there.
The shots in the senate chambers could be recolored (new color grade) and flipped to help differentiate it from it’s original use in TPM. This is without shooting anything new, but it is possible new senators could be shot with the use of green screen, but this is an idea that would require no new footage. There is also the deleted footage of the Alderaan senators that could be used in some capacity. Maybe Kor Sella could be sitting next to one of them (maybe they represent some new Alderaan colony).
The good thing is, since the speaking senators are all aliens, we can redub them to really say whatever we want. So we could throw ideas around for what they could actually say, since there have been several different ideas throughout the last few years regarding which approach to take for the political situation in the new films.