We now have these cute totes for your 20oz and 40oz tumblers. They can be used as a crossbody or a regular tote. And if you want to use it with a small handle, you can do that and attach it to a stroller or something easy for you to get to.
Material is Neoprene
Suggested time and temp 385-400 for 45-60seconds, adjust according to your heat press settings.
Make sure all plastic is not under the heat and be sure to measure your press area for sizing. They are double sided.