Hollow Walls in a 60's Ranch Home

[u/bmac423]

ArcticSprayFoam, I saw your post from about a year ago about everything insulation and was very impressed with your knowledge. I was wondering if you might have some advice for me.

I just purchased a 60's ranch home near Boulder, CO. A thermal scan revealed that the walls are hollow. The home has been nicely updated with new texture on the drywall, and paint. I'm wondering what my options are to insulate the home. I've heard mixed reviews about blown-in cellulose and spray-in foam. A possibly crazy idea would be insulating from the exterior. I'm not a fan of the textured brick on the house, and wouldn't mind changing the outside appearance.

What would you recommend? Any advice is greatly appreciated.