We are migrating to a new Marketo instance and new Marketo sandbox. Planning to connect the new Marketo instances to the existing SFDC production & sandbox instances. Wondering if anyone has experience with this. How hard is it to do a Marketo sandbox migration? We are thinking we would want to migrate the Marketo sandbox first and connect it with the existing SFDC sandbox to make sure everything is working, before we go live with the production migration. Curious if this would be double the work and if it's worth it, or would you recommend just risking it and going live with the production migration without migrating & testing in the sandbox enviroments first?