I tried commuting from Blackpool to Leeds for my Multi Engine Piston course. It's probably slightly further than you're thinking of commuting, but not too much further.
The couse is only 5 hours long, and took 3 days. At the end of the three days, I was absolutely exhausted - never again. I went back to Leeds later for my IR, and now again for the MCC, and I won't commute again - I've found some cheap accomodation nearby.
It's also worth pointing out that at the time I did the MEP course I was working as a full-time instructor, flying around 4 hours a day. So flying for 5 hours over 3 days really was a very low workload for me, and wouldn't have caused the slightest problem if it wasn't for the commuting.
FFF
------------