Inheritance Tax Question - Interest In Possession Trust

I have an inheritance tax question, in regards to IIP,

Client Brief:
• Client is Married to current Wife
• Client has two children from previous marriage only
• Wife has one daughter from previous marriage only
• Main Residence valued at £2,000,000 is owned solely by the client with the possession earmarked to pass to his children in the future.
• Wife has assets worth £450,000.

The main issue is he has an Interest in Possession Trust for the Main Residence, where the wife is the main beneficiary on her death the assets are passing to his children.

As the property is valued at £2million it will fall into her estate, reducing her estate and reducing her inheritance to her own daughter from her own assets.

Would there be a solution where in the event of the clients death the property passes for the benefit of his wife and then eventually passes to his children without increasing her estate?