Emerging nanoelectronics are expected to have very high manufacture-time defect rates and operation-time fault rates. Traditional N-modular redundancy (NMR) exploits the large device densities offered by these nanoelectronics to tolerate these high fault rates by allocating redundant resources according to the worst case fault rates. However, this approach is inflexible when the fault rates are time varying. In this paper, we propose a dynamically adaptive NMR approach by developing: (i) a genre of nanofabric topologies that supports sharing of redundancies in the NMR approach so as to adapt to the time varying fault rates and (ii) reconfiguration algorithms for these topologies to deal with fault tolerance loss caused by manufacturing defects and operation-time online faults, respectively. Simulation results verify that the ability to construct reliable systems, possibly the paramount consideration in constructing working applications in nanoelectronics, is significantly improved with the proposed flexible NMR architecture and the reconfiguration algorithms.