I've booked the Muskrat Meadows group campsite in Deas Island Park. The campsite is in a big ass secluded meadow and is the only camping on the island so there's no one to bother with too much noise. Firewood is provided and the site has drinking water. It should end up costing about $5/person to camp.

Meet at Trout Lake Park
~30 km each way (about 2-3 hours by bike).
I am planning to stop at this store (https://www.facebook.com/pages/Tidewaters-Liquor-Store/192139054304982) to pick up ice to avoid carrying it the whole way there. Alcohol is technically not allowed in the park so use your own discretion.

Let me know if you have any questions about what to bring or about packing your camping gear on your bike.

Map of route to Deas Island:
https://mapsengine.google.com/map/edit?mid=zfDH60E3-VKw.kPJpe5ddVi40

Map of route back from Deas Island:
https://mapsengine.google.com/map/edit?mid=zfDH60E3-VKw.kDAcNY2wQUD8