Ummm, exactly 2 days, 4 hours and 17 minutes. That's if you're cooking walleye. If you're cooking smallies or trout then really only a day and a half. That's in the northern hemisphere. Reverse that if you are in Brazil, or, at altitude.
Of course, all of it depends on the size of the propane bottle, stove efficiency, length of cooking time and whether or not it's a full moon! :) I'm sorry, I've had a goofy week. Someone else can probably answer this question properly.
It's all related to the BTU output of your stove. Buy a 16 Oz. bottle and try it at home before you take it up there. A 16 oz. bottle will last us ( 2 -4 guys cooking 2 meals a day ) about 3 days.
Two guys, 7 days, breakfasts, lunches, dinners and cleanup. We brought 3 bottles. Went through the first one and most of the second. Never touched the third.
"Many men go fishing all of their lives without knowing it is not fish they are after" ~ Henry David Thoreau
A typical 16.4 oz. cylinder bottle runs approximately 21,600 BTU’s. So, for a common single burner model of stove (8,000 BTUs), running at full capacity, would last approximately 2.7 hours.
So now you need to figure how long it takes to cook your fish and whether you need the stove running full bore.