This is exactly what we did. Except we were going to SL, rather than NPB.
We had originally planned to get up, über early to hit EMH, in the end we knew we were tired & had no idea how long check was going to take at SL. So we opted for booking a taxi for 8pm via front desk at the Kyriad. The taxi was late & tiny - a small sports Mercedes for 2 adults, one toddler, 2 large suitcases, a Trunki & a pram

Check in at SL was super efficient but still took quite a while, then we had to drop our bags at the luggage check, then head to the parks.
We got there before 10. This was with a 6.30 am alarm to get to breakfast for 7.
I'm not trying to be negative, just realistic. Doing EMH day one had been a major part of my plan, but the reality & our needs once there were very different.
If you miss breakfast at the Kyriad, which I thought was quite good, (hopefully I will do my trip report soon, so you can see photo's), and just get up and go and are prepared to move, move, move, it is doable.
Does the shuttle from the Kyriad drop you off at NPB?
I didn't even consider the shuttle, with so much luggage.