TexasCHLforum.com

No need to avoid IL since you have a Texas LTC. IL law allows anyone with a valid state CCL to conceal carry in your vehicle, you do not have to unload or lock in a safe, etc. You can't carry outside your vehicle. You can also "transport" your weapon in a case, say to carry into your hotel room (regarded as your residence, so legal to possess) or to carry from the car to the trunk.

This is not legal advice of course, but I also have an IL CCL (IL recognizes TX and three other states), so I am familiar with IL laws. This should give you enough to do your own research. One good resource is IllinoisCarry.com.

I would just recommend keep your weapon in your car concealed, perhaps locked in a safe when not occupied. Except for Chicago, most of IL, including LEOs are supportive of licensed carry. Although I've conceal carried in Chicago, I recommend avoiding it if you can. But you shouldn't' have a problem.