LARS NYSØM Thermo Coffee Mug to go 13oz | Travel Mug 0.38 Liter with Insulation | Leak Proof Stainless Steel Thermal Tumbler for Coffee and Tea on the Go (Taupe Brown, 12.9oz)

I use a LARS NYSØM mug, which has really good temp performance and a solid lid. I don’t use it as ruggedly as you seem to be. They claim only “up to 4h hot and 8h cold”, but it’s worth a look.