Do we have any ideas about the true size of troop numbers? Yes, we have numbers provided to us from the Sanguozhi, though I would hesitate to use the word "true." The Sanguozhi certainly gives more believable numbers, but we are still not 100% sure of its accuracy. With that said, here are some troop numbers of three famous engagements:

Guandu

In Romance, Yuan Shao's army numbered 700,000 at Guandu. In truth, his army was probably only around ~100,000 troops. One passage in the Sanguozhi states that after defeating Gongsun Zan, Yuan Shao controlled the four northern provinces and his troops numbered "around 100,000." According to Pei Songzhi's annotations in the Yuan Shao biography, Yuan Shao's expedition against Cao Cao was a major offensive and thus he must have used his entire strength. Therefore, Pei agrees that Yuan Shao's army was more or less around 100,000.

Red Cliffs

In Romance, Cao Cao possessed an army of 800,000 during the Red Cliffs campaign. According to the Sanguozhi, this was only a number thrown out by Cao Cao to intimidate his opponents. Zhou Yu estimated that at most Cao Cao had 220,000 to 240,000 soldiers. Of that, around 150,000 to 160,000 were troops that Cao Cao brought from the north. Another 70,000 to 80,000 were troops that formerly belonged to Liu Biao that was incorporated into his army.

Xiaoting

Also known as the Battle of Yiling. In Romance, the Shu army numbered 700,000 and the Wu army numbered 200,000. According to the Sanguozhi and Zizhi tongjian, Wu forces numbered only 50,000. The number of Shu forces is debatable. The Zizhi tongjian states that Liu Bei had 40,000 troops and 10,000 tribal allies. But the Sanguozhi states that Wu forces killed 80,000 of Liu Bei's troops. So Liu Bei's forces could number anywhere from 50,000 to 80,000+, but still well below the 700,000 figure given in Romance.

Did they bring their wives and family with them? Now I'm not an expert on warfare in that period, but I'm fairly positive that they did not. Bringing family members into war zones is typically a nomadic custom. Chinese armies had no such practice, as it would have been seen as a hindrance.