Deep recall for me here... I used to head to Bala for the Welsh Open Canoe symposium, which was held at the Welsh (language) national outdoor centre (not Plas-y-Brenin aka the plastic breadbin) that was on the edge of Llyn Tegid... now from memory there is a campsite near there, but I can't help much. The canoe club I used to belong to also used to do a trip to Bala and camped on the lakeside, so there is somewhere...