Now I have to say that his signs (and even his breed) do not suggest a bloat secondary to a gut twist. Often these dogs are painful, distressed, retching without vomiting and cannot keep water down (since the stomach opening is closed by the twist). Instead, I have to say that Blaze's distension with increased thirst is more worrying of a ascites (fluid build up which can feel hard if he is severely distended to the point of waddling) or a possible organ enlargement or tumor.
That all said, if this is sudden in onset then fluid is the top concern here. Fluid can come from a range of sources. We can see it with internal bleeding (less likely if that is his normal gum color), but also with heart disease, liver disease, conditions reducing blood proteins, tumors causing fluid accumulation, and infection within the abdomen. And I would note that if he has been drinking more for a while, any one of these could have been slowly progressing to the state we are at now.
In this case, as long as he is comfortable and stable, we can monitor him until his regular vet is open. Of course, if those gums pale at all or his breathing increases, then we'd want him seen sooner. Once he sees his vet, they can palpate +/- ultrasound his abdomen to see what is lurking here. If fluid is confirmed, they can take a sample of it to help diagnose what is present and therefore how we can help address this for him.
Overall, this does not sound like a case of bloat. If he had a twist/bloat, he'd not have settled and wouldn't be able to drink. Therefore, in this case, I'd be more concerned about these other conditions and would want you to have him checked once his vet is open to head off any worsening of this.
Please take care,