Travelling to the UK.

Hi there, 

Looking for some advice, has anyone travelled to UK by the tunnel recently, or are planning too? If so what exactly is needed to travel, eg: documentation. Also is it possible to stay overnight in France or is that not allowed. We really don't want to have to travel, but it is necessary as my husbands mother's house has been sold she's in care home, and he is power of attorney also need to clear the house of furniture. Would appreciate any help information. 

Thank you