Tell him to call the F&G office at Freeze Out. They will give him the scope on bird numbers, weather, ect.. I havn't been keeping up on the MT weather lately but the water should be open still, but its getting to that time of the year... They freeze up and you're screwed, most all the swawns will go south looking for open water. I would go by the last week of Oct. at the latest. The snow geese should be flocking in there any day now if they arn't already!
Look on the web and you'll find a 1-800 number that will give you the bird counts. I'd wait until there were at least a couple thousand swans on the pond if I had to travel far. Also, watch the weather, usually the first good cold snap in Canada sends the swans down, they arrive ahead of the snow geese by a couple weeks. I've typically found that on a normal year the swans are pretty thick by the 25th of October clear through mid-November barring unseasonably cold or warm weather.
As to where to hunt, the swans are about the easiest thing to hunt there. I'd just watch them for a while and see what pond they're using then set up and pass shoot them from the dikes. Thats what I did and it took all of about a 1/2 hour to bust one. I've had buddies that set out white kitchen garbage bags full of air for dekes and decoy them. Personally, I think thats way more work than I'd go through. The only advice I'd give is for a person to spank them close (40 yards and under, which is really easy to do) with #2 or #1 steel in the neck and melon (I realize they're flying but its not hard to center your pattern on the neck and head). Kind of like killing turkeys, shy away from shooting them in the body.
You're also required by law to have either a dog, a boat, or chest waders to retrieve them at freezeout.
Just read the waterfowl report in the Great Falls Tribune and it said that there are currently 2,000 swans at FreezeOut but that there numbers have peaked and they do not expect any further new migrations of Swans to come through. Just thought I would pass that along.
No big push of snow geese yet either and the pheasant hunting has been pretty difficult as well.