My Canadian husband and I (USA) would like to start filling out the forms online for Outland Spousal Sponsorship. But we might take 4 to 6 months to gather everything and complete the forms before sending. Can we start the forms without triggering an assigned number to us or a countdown deadline to submit everything and also go back to the forms at a later date and make changes? Basically, we want to be able to practice filling out the forms before we do the real submission.