Hi Kerbanauts
I've had a little play around over many, many hours on enhanced and I've come across a way to circumvent the time warp Crash.
It's not ideal but works every time.
I hit time warp at full speed for about thirty days. Try to save or recover. If it doesn't work, full warp for 40 days. If it doesn't work, full warp for 50 days. After which it always allows a save and goes back to responding normally. I'm on xbox one. Hope it works for you guys too.
Phil v B