Hey Tom,
This sounds like it is probably something to do with your setup, we do ignore timeouts as much as possible during upgrades/installs. This update in particular does have a couple of database upgrades that could take a while, perhaps try running the upgrade through the console? Just open your console (shell/cmd) and navigate to the Totara code and run
"php admin/cli/upgrade.php" that should let it run without timing out.
Cheers,
David