On the basis of numerical calculations, the feasibility of the implementation of a time-of-flight small-angle diffractometer at the IBR-2 reactor optimized for a neutron moderator operating in cold (temperature 30 K) and thermal (temperature 300 K) modes has been studied. In the cold mode, the maximum of neutron energy spectrum of the beam is shifted to the low energy region (large wavelengths), which extends the sensitivity range of the facility with respect to the sizes of the objects under study (1-100 nm and higher). A classical scheme for the separation of thermal/cold neutrons (E ~10-3-10-2 eV) from the background (formed mainly by fast neutrons) based on curved neutron optical devices has been considered. Due to size constraints imposed by the channel geometry, a configuration with a short multi-slot beam bending device (bender) is preferable. Modeling and optimization of the proposed small-angle facility have been carried out taking into account the real geometry of the channel and the available space in the experimental reactor hall. A comparison has been made with the facility based on the curved neutron guide and the facility with direct view of the moderator.