We have done hwy 1 going north in our previous 35ft motorhome with toad. For me it was an easy drive except for 2 right hand curves where the toad mirrors almost hit the cliffs. But I am also used to driving in the mountains and hwy 1 is much straighter than most of those.
We now have a 41ft motorhome and I do find that the extra 6ft makes a big difference on the mountain roads and I wouldn't take it on hwy 1.
We don't have a tag axle so it probably would not be noticed, but you have tag axle so I am sure it would be obvious that you are over 40ft.
Also, since you are coming down from Alaska, I don't think that you would need the extra trip down hwy 1 for the scenery. There are lots of other ways you could get to Texas from there.
David