Any advice on commuting Bristol to Cheltenham?

[xkcdfangirl]

do you (or anyone you know) do this?
is this a crazy idea?
Google directions say door-to-door by car would be 60 mins - how much more would it actually be allowing for rush-hour traffic? Can I assume the motorway bit would be pretty clear if I left at 7.30 ish?
What about returning in the evening?
Planning a trial-run anyway but that will only give a single day's snapshot so would love to hear from someone who does this regularly.

Borrow someone's TomTom Traffic and plot the route every morning for a week... watch the time in the corner and watch the sidebar for traffic delays to get a decent idea without driving anywhere. That's how I did it for finding my safe commuting distance.

My husband travels north Bristol - Stroud in 40 min ( non rush hours).

I do Horfield to Cheltenham for uni one day a week. It takes at least 75 minutes, partly because the traffic in Cheltenham is terrible. I do M32 and M5. The traffic to the IKEA junction down Muller Road is so bad that I go down to the St Pal's junction.

It's a tiring journey, especially the motorway, and I can't wait to stop. Sorry!

My husband does Bristol to Gloucester every day. we live very near the motorway one end and he works 5 mins off the motorway the other. It takes him 40 mins leaving Bristol at 7.15am.

Thank you!
No idea if this is going to happen but useful to know.
Seriously considering getting a TomTom though - hadn't clicked what they can do but when I looked at the route in the peak of rush hour and one of the roads was snarled up, it happily plotted an alternative route avoiding it. This newfandangled technology what will those boffins think of next...

have you considered car-sharing? i used to do this commute the other way round and shared with a couple of different people at different times - there are quite a few people who do this commute i think (google car-sharing websites to find people). might be worth considering