Your LSTM class is undefined, so I just used nn.LSTM with a hidden size of 1.
As expected, the model just uses approx. 100 MB on the device:
model = Sequential('resnet', 100)
print(torch.cuda.memory_allocated()/1024**2)
> 0
model.cuda()
print(torch.cuda.memory_allocated()/1024**2)
> 105.92431640625