We highly recommend booking accommodation as soon as possible, it's looking like a very busy weekend in London!
The closest accommodations to the reception venue:
Premier Inn, Hackney and Kingsland Locke, Dalston,
We have provisionally booked rooms at Kingsland Locke (where we're staying), if you would like to take us up on this let us know when you RSVP and we'll send you our personal booking link. Give us a shout if you want more details.
Other local hotels:
https://getsomekip.com/ - this is good value if there's a few of you willing to share one room.
For more cost efficient options - there are lots of lovely Airbnb's in the area which are great for groups, or anywhere further North on an easy tube line.