Our new house will not have internet for a few week, and I would like to setup a tado Starter Kit V3+ system with wireless smart thermostat before internet arrives, just to have a thermostat in the house to control the boiler. Is this possible?
Not possible. You need access to the cloud servers to configure the devices. If the interface to your new boiler is the same as your current boiler, then you could setup the system in your current home. The devices will configure and download the latest firmware, then you can power them down and take them to your new home. The devices won't know they've moved location, so you'll be able to use manual controls until the internet is available.
@henrivk You can, of course, buy mifi devices with an ethernet port which can be very useful if your broadband is a tad flaky!
Thank you all very much for your useful comments and suggestions.