We have recently set up a TensorFlow assessment function in AWS lambda, and got very close to the maximum allowed size of a lambda function (250MB) with the trained model currently being 85MB, and the TensorFlow libraries and binaries taking up another 140 or so megabytes by default ( I feel like Amazon could do some work in this area to support users to use their own engines and not be bound to AWS AI Platforms and…
It sounds like you're stretching to make the use case fit inside a Lambda. Have you considered extracting the assessment functionality into an SWF activity, invoked from your Lambda via StepFunctions?
We considered running it on EC2, but the economics just didn't work out for our needs (hundreds of parallel processed jobs with irregular spikes, <5s runtimes per invocation and some others)