Tire issue with honda Accord 98.?

So this weekend im planning on driving 150 miles (hwy) then from there 190 miles (hwy) the weather is pretty sunny but the problem is i did the penny test and my tire tread is up to the top of lincoln's head a little more a lil less depending where you place the penny. do you think my tires will be fine? i dont have money to replace them right now. can you give me a few tips on how i could make the drive easier on my tires thanks!