But AWS (maybe others as well) only lasts for 1 year and lambda and stuff might have higher free tiers but stuff like EC2 barely covers a T1 micro IIRC.
You can sign up new accounts, even on the same credit card. Additionally I believe that if you contact support and agree for them to wipe all the resources in your account - you can have another year of free tier again.
And of course, you're deploying all your stuff automatically anyway right? So wiping the account doesn't really matter.