My question is do I need to disclose the death to renters
You are going to completely refurbish the house. Nothing will remain in the house that belonged to the previous owner. I see no need to disclose anything to renters.
I know I do need to disclose if I come to sell it
Not that I plan I selling it anytime soon.
There's nothing in the Law Society's TA6 Property Information form, or in the TA6 Explanatory Notes about disclosing a death (recent or otherwise).
See
https://www.lawsociety.org.uk/topics/property/transaction-forms