Is DVDshrink crashing, or is Video Studio crashing?
I don't remember ever getting a crash with DVDshrink... All of my Video Studio crashes have been caused by the particular file... I usually don't know what's "wrong" with the file... I've just noticed that some files cause a crash and others don't. (If you have a corrupt file, you may be able to fix it with a 3rd-party program.)
What format is your original file? The size of your original file isn't usually important, because unless it's DVD-compatible MPEG-2, it will have to be re-rendered anyway.
File size depends on
bitrate (and playing time). Here is a handy
Online Bitrate Calculator. (If you configure your project settings for a lower bitrate, your file will be smaller.)
Am I doing this right or is there another way of doing this apart from putting it on to two dvd.
You could use a dual-layer DVD, but "burned" dual-layer DVDs can be flakey. As a "rule of thumb", you can fit 90 minutes of commercial-quality video and Dolby audio onto a sngle-layer DVD. And personally, I try not to "push it" much beyond 2 hours, because I start to notice the quality-loss.