Yes maybe it's a little small for a Solar; I have made it by eye. Unfortunately resizing it now present some problems, first the skin will turn distorted when I activate "resetXform" to the bones, in NWMAX (which is needed to save the new scale). Second the base of the new bigger scaled creature appears a little under the ground level, in game; for some reason that I don't understand. So it would be difficult to fix.
To conclude I would like to say that this would be much easier if D&D uses the metric system, in their creatures descriptions, like the civilized people...
I may be running a modified version of the NwMax 0.8 scale wizard, but if you simply use the wizard, and then turn off and back on the skinmesh "always deform", it should fix any issues you may have with the scale. Simply select the aurorabase and resize the entire thing at once. After you scale it, go back to the aurora base and set the animation scale back to 1.0, since your scale is now burned in. If the model has position keys in its animation, there could still be problems, but usually, the only position keys are located on the rootdummy, or whatever the model uses for a root node. In a perfect system, there are no position keys, so I tend to delete them and see if the model still runs smoothly. In GMAX, position keys are commonly automatically created when you make rotation keys. I delete them all in mass when I am done with the new animation I am working on, and it works just fine. This is how I have been scaling balor, nycaloth, and my fallen solar models, all of which have skinned wings and tails.
Edit (about metrics in NWN):
When I see a description in feet, I go to google and request "convert feet to cm". It brings up an in-google conversion tool. I type in my feet I want converted and grab the resulting cm value. Then I go into Gmax, select the model in an upright or walking pose, preferably the head node. Now find the topmost node in the head and get its cm height value (granted your Gmax grid setup is in cm). Then I take the number I got from google divided by the current cm value of the head node and multiply it by 100 to get my scale wizard input. Bingo, perfect height rebuild.
I also have an unreleased mini-function to add to my gmax library on the vault. It has a function called resetScale. Just tell it in the maxListener window to "resetScale selection[1]" with the node selected you need to bake the scale on. It forces a XForm modifier into the first position in the stack, bakes the pre-stack scale you have created on the model node to that model, and collapses only that modifier to the node, retaining the rest of the modifier stack.
Edit Edit: I take it back, it does NOT keep the pre-scale modifier stack. That is another function of mine. I should do that with all my reset functions though. But it does bake the scale of all child nodes in the tree starting at the selected object.