When baking berry scones, the texture is too moist & spongelike. To make them drier - would you cook longer, at higher heat, or use less butter/cream?

For the same reason you describe, I use dried fruit and berries in scones because the dough is dense enough that it tends to shred fresh fruit. I always rehydrate dried fruits (cranberries, blueberries, apricots, etc.) in hot water to cover for 15 minutes, then drain them well before adding to the dough.

I'm guessing too much fruit, also. Berry scones can be tricky. Be frugal with your additions, especially fresh berries. My ratio is a very scant 1/2 cup of fruit per batch, and that seems to work well. I always freeze my berries, which minimizes mushing of the fruit when mixing the dough together. Good luck!

I agree with Nancy -- try to minimize added moisture from the berries. In particular, berries that have been frozen can weep a lot as you mix them into the batter. Depending on your recipe, adding them to the batter straight from the freezer can work well. They will only release their moisture around each berry while baking, and the rest of the batter stays drier.
I also prefer to add berries or other fresh fruit after mixing the batter, by patting out the scone dough into two rounds, scattering the berries on top of one, placing the other round on top and pressing lightly to stick them together, and then cutting the scone wedges from that. This really minimizes how much the berries get mashed and prevents much moisture from getting mixed into the dough.

I'd suggest you use less fat - butter, cream, sour cream, whatever the fat you're using, cut it back and substitute enough liquid - try milk - to bring the dough together.

Your previous success with the batter suggests the problem is not there, nor in adjusting the butter or cream. A hunch, perhaps there were too many berries or they were too moist. next time use fewer berries, or drain them, or both, and see if you get better results. Or don't bake them in the scones...use them as a luscious topping.