… camino a su destino y Paúl se las veía

… camino a su destino y Paúl se las veía negras para alojarlos en la escala parisina. Does “se las veía negras” refer to how difficult Paúl found it to house people in Paris?

This seems to me to be a correct interpretation!

Yes, it’s correct
“vérselas negras” = struggle, find very hard

Yay!