At the RI-MP2 level, the DLPNO approximation reproduces canonical intermolecular interaction energies with relatively small errors, even in percentage terms, but DLPNO errors increase with molecular size. Whereas "loose-MP2" PNO thresholds 95 (T CutPNO = 10 -7 ) are faithful to within 3% percent of the canonical result for small dimers, much tighter thresholds (T CutPNO = 10 -9 ) are necessary in order to come within 1-2 kcal/mol of the canonical RI-MP2 result for nanoscale van der Waals complexes with 100 atoms. Alternatively, extrapolation to the canonical limit (T CutPNO → 0) affords good results when only T CutPNO = 10 -8 is feasible. This is true even for large complexes involving C 60 and C 70 with an equally large partner. Notably, counterpoise correction significant reduces the DLPNO error for large systems and should be considered mandatory when DLPNO approximation is used for intermolecular interaction energies.