Sensible assumptions but, my experience is that reality can be very different.
A different airline, for sure, but I was checking VA's estimated departure and arrival times the other day using the net and they certainly didn't resemble the real situation. So, yes, you can use your mobile but with the distance between terminals you might regret that you trusted what you read. I'd prefer to follow the screens and announcements and, as you would probably be aware, those too can be far from accurate.
Yes, reality often has no sense or logic!
Screens inaccurate ... Yes, quite aware they can be! I recall getting to MEL for a VA flight to SYD a little later than I should have a couple of years (arrived at 6.15 am for a 6.30 am flight), only to find no mention of my flight on the screens! I eventually found out it had been cancelled, but I would have thought it would have shown as such on the screens! No communication from VA though.