Cornwall gets really busy in the summer so or Airbnb will probably be your best bet.

There is also camping onsite at the wedding venue.

The Barn at Pengelly, Trispen, Truro, UK
(Pengelly Farm, Trispen, Truro TR4 9BG, UK)
01872-229842

If you would like to camp on site then please email the venue directly to book this at
camping@pengellyweddings.com
Camping is £20 per person and this covers two nights (27th and 28th). There are hot showers and toilets available for anyone camping.