Are you an engineer and coding on a daily basis? If so then taking some time off and doing your startup should not hurt you too badly. Why would you move at all instead of just keep renting and working on your project and cut your expenses other than rent a bit to keep in your networks.

Maybe negotiate to change your role to something you would be happier doing?

500k/yr is a crap ton of money to let go. It depends on how miserable you are but I would have to be seriously seriously miserable to drop that gig.