Yep. Just like brewing an extract batch where you add water to the fermenter after making your wort. Go easy though. The gravity will drop faster than you think and you could overshoot where you want to be.
I brewed 5 gal batches with a 10 gal cooler for a few years and no issues. Most were around the same ABV as yours, some higher. Get the 10 gallon, you won’t look back.
I like my wort into the fermenter at the temp I’m fermenting at. Usually 64-68 degrees. In the cooler weather I can get that with one pass. Kettle to fermenter.
In the summer though, the ground water is a bit warmer so I have to recycle it back to the kettle for 10 mins or so.
Never had issues...