In reply to tehmarks:
I worked in Hemel for a year, living in Blackpool. The driving was pretty brutal, particularly in the winter. Had a few near misses that made me question whether it was worth it. I needed to be on site before 8am so was getting up about 3am on Monday morning. After a while, I reverted to leaving at 11pm on Sunday night and getting some kip once I got down there. I had a room in a houseshare.
The drive back on Friday isn't too good, but that's identical to a drive to climb. M6 toll tag helped with the queues.
I did a few weeks using the train, booking well in advance, sometimes 1st class for similar price. Friday night sat on the carriage floor isn't great.
Drinking with workmates on Thursday night is very tempting. Instant regret on Friday afternoon.
My only advice would be to try and engineer avoiding busy times to travel. Get creative with travel plans to avoid hours on the M1/M6. I've flown places from London airports midweek and met people at the destination, avoiding the trip home first. If the weather looks wet for the weekend, just stay down south and take time off when it's dry.