Texas in September, it'll still be HOT! Unfortunately we really don't have a Fall.

There's nothing like driving home from a Bash thru Baker CA with the temperature sign reading 105°. I then decided to install AC on my hot rod. Give the trip a shot without AC, it'll let you know if you need the comfort of AC.

Yep
What Rudi said. Having integrated defroster is worth its weight in gold, when you need it.
WYAIT, consider adding intermittent windshield wipers.  That is one of the best mods I ever did on my 66.

I have a couple of non AC cars that are unbearable even just around town in the 100* summers. I rode with RPM to the 2023 Bash in New Braunfels. Can't really imagine doing it without. Sure, somehow I survived until I was about 25 in the same weather in cars without A/C, but I was a lot tougher and more resilient then. 
100% yes on reviving your A/C system. Ol' RPM is a man of few words. Very few. Remember what he said on the mic at the 2024 Bash? Yeah. Me neither. 
But his actions speak volumes. He spent a zillion hours and a fair bit of coin chasing down parts to use OEM bits in a non-A/C car. He fabricated the compressor mount and moved his accessories around to make way. And it was worth it.
Yours being an A/C car will be far simpler, much less hassle. 
 

Jim Bowie wrote:

We did two Bash run to Texas with to 66 pony, the only air we used was open all the windows, and don't stop. I don't know but we might have one more bash on the bucket list left. We'll see.

That's the same a/c system I use - the 460 system. Four windows down at 60 mph.
 

Keep us informed.  My 65 vert has underdash ac. I will have to decide whether to go with a modern Sanden compressor and condenser with the original underdash, or go with Vintage Air so I get conditioned defrost.

I tend to agree, Rudi, but the convertible will get very limited road trip miles, so the underdash would be simpler, plus it will make a lot colder air than a Vintage Air setup.