There aren't a lot of martial arts historians in this sub, so while it's possible you'll get answers here, you might try x-posting to /r/WingChun, which I imagine would be the sub that could have the most information on Ip Man's life. In fact, a quick search of that sub turns up several existing questions about the films.

I realize I'm a little late to the party here, but I wanted to chime in. This is as much a historiographical question as a historical one, meaning that a lot of work still needs to be done in evaluating sources and the like.

First, be very careful with what is said in /r/wingchun. I found that place to be fractious and to have an emphasis on why one given approach to Ving Tsun is better than another (or why Ving Tsun is terrible - I was downvoted for talking about holding my own against other systems).

The other thing is that it's tough to know. There's not a lot of written records, and while there may be journals and the like, they're not widely available. Every school has their oral history, and there are a lot of claims out there that are highly questionable (see for example William Cheung's claim that only he was taught true Ving Tsun by Ip Man). There's a lot of potential for making stuff up for the purposes of money and/or prestige. Even the Ip-Man-authored history, such as I've been able to find, is mostly writing down the oral history (and makes no mention of his time in Hong Kong).

I wish we could do better, and as both a history buff and a passionate student of Ving Tsun, I'm trying to figure out some way(s) to do so. Unfortunately you have a lot of statements made out of self-interest that lack corroboration (or any way to corroborate them, really).