These have all been created with the base SDXL release + refiner in Automatic1111's using the extension to add the "refiner" found (https://github.com/wcde/sd-webui-refiner)

1216x832 resolution with Hi-Res Fix at 2x using the Siax-200k upscaler and DPM 2 a Karras sampler.

Here's the dynamic prompt. You need to install the dynamic prompt extension from (https://github.com/adieyal/sd-dynamic-prompts)

This is the prompt I used

{cinematic shot | establishing shot | intimate scene | sweeping grandeur},(21:9 aspect ratio)

{(ultrawide panoramic cinematic aspect ratio)}

{Blender | Photoshop|Octane render|Unreal Engine 5|8K RAW Photo} ,  

{2-4$$lone twisted tree | winding river| mountain peak| crumbling ruins| abandoned cabin|wooden fence | dramatic cliffs | stormy sea | rolling thunder | howling wind | foggy moor | charred forest | broken-down cart| towering dunes | parched canyon | bone-strewn pit | petrified woods| wrecked galleon | beast's den| majestic waterfall | calm lake | moonlit trail  | moss-covered stones | misty vale |ravaged battlefield | derelict mill}   

{cirrus clouds |stormy sky|cumulus clouds|stratus clouds|nimbostratus clouds|cumulonimbus clouds}   

{clear | atmospheric fog | mist | haze | pollution| dust |smoke |atmospheric halo| sun dogs | moon dogs | sun pillars | circumzenithal arcs|circumhorizontal arcs},

{abstracted | concept art| Hyperrealistic| stylized| fantasy| impressionistic | photo| realistic }   

(16K, 32bit color, HDR, masterpiece, ultra quality)   

{brutalist | minimalist| whimsical| retro futurist}   

{muted tones | vibrant hues}  

{warm sunset tones |cool muted blues | colors}   

{natural | warm| dramatic }  

{god rays | sun beams | crepuscular rays| antisolar rays | volumetric light | light pillars | sun pillars | moon pillars},  

{dawn | sunset| night} {clear  | overcast | fog}   

{winter | spring | summer | autumn}   

{ volumetric shadows | volumetric ambiance | aerial perspective | depth fog},       

in the style of  
{1-2$$Dylan Furst  |Ash Thorp | Simon Stålenhag | Bob Ross| Ralph McQuarrie | Syd Mead| Moebius| Daarken| Felix Yoon| Gustave Doré| Arnold Böcklin| William Blake | Frank 
Frazetta| John Constable |J.C. Dahl }   
and
{1-2$$James Gurney | Craig Mullins| Android Jones |Justin Maller | John Berkey| Roger Dean| Rodney Matthews | Chris Foss| Nicolas Roeg | Geoffrey Hayes | John Harris| Dinotopia| Jon Foster| Brom| Brian Froud | Alan Lee},

Came out pretty good. Generated at 2048x1024 then upscaled 2x in img2img. No Refiner.

`cinematic photo breathtaking High Quality, Award Winning, photorealistic, realistic, photograph, landscape of a Overwrought Seductive The Nidhogg Dragon from inside of a Savanna, Hazy conditions, 50s Art, Alabaster lighting, film grain, Canon EF, Circular polarizer, Kodachrome, matte, subsurface scattering, radiosity, studio quality . award-winning, professional, highly detailed . 35mm photograph, film, bokeh, professional, 4k, highly detailed

(low quality:1.4), ugly, deformed, noisy, blurry, distorted, grainy, drawing, painting, crayon, sketch, graphite, impressionist, noisy, blurry, soft, deformed, ugly

Steps: 20, Sampler: DPM2 Karras, CFG scale: 7, Seed: 1207805303, Size: 2048x1024, Model hash: 31e35c80fc, Model: sd_xl_base_1.0, Variation seed: 3557558652, Variation seed strength: 1, Clip skip: 2, Token merging ratio: 0.1, NGMS: 0.4, Version: v1.5.0`