The Build-up
At submission sketch out a viva prep plan.
You might not know your viva date but that’s OK: you know your current situation. You know how busy you are and you know what responsibilities you have. With a little reflection you can also get a good feeling about how you need to approach getting ready.
A sketch of a plan can take account of busy-ness and obligations. Do you need two weeks to get ready or is it safer for your stress and your time to have a month? Sketch how you would do the work.
Start small and build. Day one of viva prep doesn’t have to mean reading your whole thesis, checking ten papers and having a mock viva. Build up to that. Read a little and then do more the next day.
The last week of viva prep will probably be busier than the first – but the last day might be more relaxed as you realise you’ve built up everything you need for meeting your examiners.
After all, you’re building on solid foundations.