Free will is more about conscious choices than choice made on impulse. With impulse the choice is made for you. On the other hand, if one was to infer a course of action, which is optimize, and willfully take that course, that is free will. To avoid irrational choices, which through impulses chose for you, is also part of free will.
In heaven, I assume one will chose what is already there, since it is already optimized. The advanced free will would independently infer the same optimized choice and then use will free, while still fitting in perfectly.
If you are more like an animal, acting on impulse, without any logical way to compare alternatives for optimization, beyond short term feelings, heaven might seem like it is forcing a choice and a direction. But if one can reason and extraplate into the longer term optimizations of nature and the universe, you will freely chose to align oneself with what is already defining optimization. Free will in heaven assumes an advanced enough mind to see optimization, independently. One would choose this and then find themselves aligned, naturally, because of their free choice.
In hell, the choices are make for you. You do not have free will in hell, unless your mind works in terms of de-optimization. You can't think in terms of long term or short term optimization (nice feelings), since both are constantly deoptimized (punishment).
There is a loop hole in hell for free will. For example, someone who likes to cut themselves and inflict self pain might have free will in hell, since cutting and pain, both which de-optimize, may be a normal day in hell. This type of free will would not be based on sanity, but wuld be insane free will; irrational impulses that deoptimize. One might get a promotion in hell for this.
I was just playing the devil's advocate, using the assumption that heaven and hell exist and how free will could come into play in each realm, as they are defined. I am not saying this is true, just inferring.