Commute, well forget the M1, you might arrive as the flight returns back to the UK. Check the Highways Agency web site relating to the works north of the M25.
M40 is okay, but then you hit the M25. Depending upon what time of day, the weather and accidents, you might be lucky.
As it is a new job and arriving on time is of paramount importance, forget commuting, unless you allow a huge contingency period.
I guess it boils down to ensuring you arrive at work unfatigued, only you can make that decision.
Personally, if the job means a lot, commuting should be kept to 60 min or less without in built contingency.
Would I do it? I am M25 worldly wise, so no.