Alt route around Houston

Not only have I drove it, but I live on 190 in Louisiana.

Depending on your starting and ending points though I would suggest taking LA 26 from Jennings to DeRidder, some of 26 has narrower shoulders than 190, but it is still a good highway and will save you miles. I don't like taking 190 across Texas much west of Livingston, TX as it becomes a made up highway that zigzags its way across the state adding lots of miles just to stay on the same hwy number. If going north on I-35 you are probably better taking 190 to I-45 up to 84 then across at Mexia.

For diesel options while towing (I have a diesel F250) my picks going east to west would be:

a station on the left on the 1/2 mile south of Longville, LA (tiny intersection town), big truck style diesel pumps though,

On the extreme west side of DeRidder, LA on the left near the airport Holidays Exxon (another small truck stop, but with limited hours of operation)

There is another Truck stop with diesel on the left in Merryville, LA

Once in Texas the next good easy access diesel is at the indian reservation gas station between Woodville and Livingston, this one is on the right side of the road, just be careful turning into and pulling out of the parking lot, I drag my hitch there on my motorhome, there is a side road with better approach access just west of the station.

I can't think of any particularly good stations as far west as Huntsville, although I am sure there are some.

When I was there last fall in the motorhome there was a fairly rough section of 190 around Huntsville TX, thankfully it was only a few miles, also as of a few months ago there was bridge replacement going on between Jasper and Woodville with a single lane section of road controlled by traffic light. This area had detour signs for wide loads to go miles out of the way to get around, but I had no issue with my motorhome, just 1 lane with concrete barriers on both sides for a few hundred feet and a low speed limit.

The road is good especially the Texas portion and there are many reasonable sized towns so fuel shouldn't be a problem.