Your options differ depending on the fish. The lake trout with the orange meet can be cooked any way and are excellent. The white meat ones are so fatty your options are somewhat limited.
I agree with this statement. Another option besides smoking is to par boil the fish first to get some of the fat out then cook as you wish.
Put the fish in a shallow pan with some aromatics (onion, celery, carrot, parsley, salt, whole black peppercorns is traditional), cover with cold water, put the pan on medium heat and lid it up. After about 8-10 minutes, the water should be close to a simmer and the fish should have let go a good bit of fat into the water. Remove the fish to cool and use it however you want. It won’t be as good as other kinds of fish but it’s better than nothing. Good luck.