Being texted the route the night before is more than you should be expecting (and more than you'll get on your test).
I actually suspect the instructor is probably feeling generous providing this earlier than the 2 hours and a little part of me sides with him/her.
To be honest I would have expected you to be able to cope with that pressure/time frame although not communicated via text.
It does seem like a rush sometimes, especially at the beginning. My recommendation is to prepare and plan absolutely everything else you possibly can well in advance. If you're off blocks at 12, by 10am I would recommend being showered, dressed, at the airport, aircraft checked out (if on the ground) local notams checked, weather brief prepared etc etc. That way once you get your route your workload is minimized.
Totally agree. I think an 8am wake up on the day of CPL training then a 2 hour run is taking the biscuit a little... I would have been in at 9 taking care of those - ready to receive route at 11am - because I know I never got more than 45 mins towards the end of my training.
I personally provide the Navigation briefing - give the first route over night to be planned then meet an hour before the flight to go over the planning.
I then progressively reduce the amount of notice given for Nav route from 3 hours to then 2 hours and then reduce by 30 mins intervals till I hit 45 minutes notice for the last couple of flights.