ExCeL London has seven on-site hotels, ranging from budget to luxury, offering 1,600 rooms between them. You'll also find a further 10,000 rooms within 20 minutes of the venue.
Holiday Inn Express Excel - more details.
Ibis Styles London Excel - more details.
Holiday Inn Express, Royal Docks - more details
Ibis London Excel Docklands - more details
Our advice would be to visit www.booking.com - look at the options, check the offers, reserve the best deal - but know you do not have to pay for it until that weekend. Keep checking the offers and adjust when and if something better comes up.
Or down load the AirBnB app - there are plenty of options nearby.