You can acces any module easily and save as many as you want.
Like
net = Net()
Do stuff
torch.save(net.conv_1_1.state_dict())
torch.save(net.whateversubnewtwork.whateversubsubnetwork.state_dict())

Do whatever

net.conv_1_1.load_state_dict(torch.load(weights.pth)) #maybe it was not load_state_dict but something like that, just forgot right now
and so on