Well.... Hm...
My advise may be different depending on your boat and setup, so please share that info when you reply. I am curious if you are saying in your post that you usually go over to Kelley's to put your boat in? That would make me think that you are in a smaller boat and staying close to the island. If that is the case then you won't want me telling you to go to Niagra Reef, even if that is where the fish are.

10 days from now is a tough prediction. Make sure that no matter what I say or anyone else, you should check back a few days before and the. Keep checking this forum until the day of your trip.

The Walleye typically move with the water temps.. Yes, there are other factors too, but water temp is a big one.
This time last year there were walleye being caught right up the middle between SB and Kelly's
2 weeks ago some boats did well North of Kelly's. A couple weeks ago I marked a ton of fish just a couple hundred yards West of Kelley's.

However, in the past week the water temperature has actually dropped! Not something that is super common right now. With the current weather and the way things are looking, it might be a little bit before they are "slamming" them around Kelly's. The firing range has been great when the water isn't mud. Niagra is still good. Early I. The morning the ferry channel is usually good for a couple tickets. All of those areas are better served from launching from Catawba or even Mazuriks in my opinion, unless you are staying on Kelly's Island.

As the water warms up in he shallow Western Basin the fish move East. They will move from the far West and West side of the islands, to the South and middle of the islands and Gull, etc.

The jig bite is directly tied in with spawning. Which is also tied into the water temp... If you are going to jig, the best place to be in the next couple weeks is West of Catawba on the reefs. Look at a map of the firing range and Che k out the reefs. Jig bite has been on and off with the weather.

I know that I didn't give you the crystal ball report, but that's about as good as "I" can accurately tell you 10 days away and the weather the way it is.
If you go to Kelley's and North of it on the 17th, you should see and catch some fish. Typically they are around and can be caught that time of year over there. But water temp and clarity have a lot to do with that and that is changing daily.

I'll give you better ideas closer to the 17th. Please do tell us if you are trolling or drifting, and size (or type) of boat and gear you are using.

-Matt