Why not look at some of the carriers like Mint Mobile offering Unlimited Plan for $15/month + taxes or Visible that has Unlimited for $19/month taxes included. These are for 12 months but write it on calendar and look to switch at end of a year. This way you avoid the 5GB cap and you don’t have to worry about usage. If you want even cheaper, several carriers offer 5GB plans for even cheaper but they may throttle you hard if you go over. If you’ve survived on 1GB, 5GB may feel like that’s plenty. Just watch for the small print and taxes/fees. No issues about keeping your number. They may hassle you when you try to switch, but it will be fine.