In normal circumstances, the purchaser's solicitor would require your solicitor to prove evidence that you have paid any LPT and household charge plus interest due before the sale could be closed.
However, if you inform them that you have deferred the tax, then I would imagine that your solicitor would have to undertake to the purchaser's solicitor that he will pay the LPT plus all interest due to Revenue directly from the proceeds of the sale. So you wouldn't get your hands on the full sale price, but only on the net amount after the LPT due has been paid in full by your solicitor.
You'll need to clarify this with your solicitor when you put the house on the market.