I think 75F is o.k., but it's right on the edge of too cool. You should keep a close eye on it. You don't have any wiggle room. Personally, I'd add the CHE, or heat tape if your enclosure is made of pvc. It will give you more control over your enclosure temps.
Hello again! Yeah, you make a good point, the 75F might not hold up as well in the Winter, better safe than sorry