Just keep lowering the send amount until it goes through. That's really the only way. So try 100k, then 95k, 90k, etc. and continually drop. Once a transaction sends, start at the top again (100k, 95k...) and keep doing that until you've gone through all your coins (cycled). And then you can send ALL the coins in one (hopefully) transaction a final time.

You can also use coin control to go through and select... say 75 inputs at a time. Then at the top of the client you can see the total you can send (after fee), so input your address to send to, the after-fee amount, and that will knock out 75 inputs. Then just keep doing this over and over and watch the input list drop, .