Any other previous Pi model should work right out of the box with a Sense Hat. 3B+, 3A+ etc. My two Sense Hats are running on older Pi A+'s. Both are headless setups with no keyboard, mouse or monitor attached. I will likely upgarde one of them to a 3A+ at some point.
If you are looking for an alternative to the Sense Hat, the Pimoroni Enviro+ comes to mind. I don't presently own one and can't comment on how well it does or doesn't work. I have been thinking of buying one though. They are a bit pricy compared to a Sense Hat though.
https://shop.pimoroni.com/products/env ... 658457171
At some point I would expect the current glitch to be fixed and the Sense Hat to work with a Pi 4. The heat given off by the Pi 4 may be an issue though as its going to affect the temperature reading on the Sense Hat. My Pi A+'s caused my temperature readings to be artificially high.