I see you have a rather nice £1,700 hardtail which I'm guessing may not have bosses for luggage, so bike packing bags may be your only answer.
Provided you can carry all you need securely it doesn't matter how you carry it.
MTBs are not set up for mileage, but if you are confident you can do the required daily distances comfortably, there's no reason why the Whyte couldn't do the job.