They can still do 3 daily flights. Remember the smallest equipment they have is the A330. It would be possible for them to do another increase in available capacity by going for an A330, A380 and 773 scenario with the 773 also having a 1st class cabin with Capacities roughly 285+517+354 respectively which would be further 400 seats a day (assuming they use the A330 as a 2 class aircraft). But I’m sure that any based line engineers wouldn’t welcome 3 aircaft types to service.
And in case anyone’s wondering, I believe they have no fewer than 7 seating configurations for the 773s: 4 are 3-class ranging from 354 seats to 380 seats and 3 are 2-class ranging from 427 seats to 442 seats.