When you substitute classifier with your own, you need to check the original model classifier input dimensions. Apparently, the original model classifier linear layer input dimension is 2208. So, I can do forward without error with this code
model.classifier = nn.Sequential(nn.Linear(2208, 256),
                                     nn.ReLU(),
                                     nn.Dropout(0.2),
                                     nn.Linear(256, 10),
                                     nn.LogSoftmax(dim=1))

You can check the model by simply print it like print(model)