No where in Rutland is Cheap......well not for a scottish yorkshire man
The cheapest is probably the Fox & Hounds at North Luffenham...about 1.5miles from the lodge....it's about £40 b & b...it's ok for a pint or two and does bar snacks....it's ok as well on a Friday or Saturday night
Noel Arms at Whitwell is also ok but a bit more expensive
Failling that you'll need to stay in Uppingham or Oakham......and have a choice of Pubs because to get a taxi anywhere in Rutland is expensive.
But I would book up early...there are loads of sailing , bird watching and other events on so availability is scarce and prices high..
Or you could camp in a tent.....there are plenty of cheap camp sites very close to the water....Ie.Wing or Opposite the Sailing Club, Pheasents Roost Manton Besides Rutland lodge has a decent hot shower for anglers.