You will have a project manager who will work with you to migrate your self-hosted community to our Cloud. The import process is typically pretty smooth. However, I do want to stress that we can only import what is provided so ensuring a complete backup is taken is always the best way to ensure a positive migration experience 🙂 .
Our support timeline can be read here: https://invisioncommunity.com/legal/standards/ . I'm afraid, I cannot guarantee that you will get a 15-30 min response rate 24/7 but during regular business hours, we are very quick to respond and we do have monitors in place to warn us about issues happening in our environment that we have people in place to resolve as quickly as possible.
We do not have an automated backup process that you can perform and hold offsite. We have rigorous backups in place to handle this for our clients but we can provide you with periodic backups on request.
If your user base is in the UK, you may wish to look at our EU hosting location which comes with our Creator Pro plans and higher.
If you wish to move forward, I am happy to move this to our sales team to help you continue investigate if this is right for you.