Try it one day on the weekend. That will give you an idea how long it will take and the effort. Bear in mind that the traffic will be lighter on the weekend but that should not affect your time too much. If you cruise at 20 mph and it is relatively flat, I would guess it will take you about 90 minutes each way factoring in stops at stop signs, traffic lights, etc. Add another 15 minutes to freshen up and get dressed for work.

If you feel confident after trying it on a weekend, then give it a try once or twice a week. Then bump it up when you feel ready.

Here are the three commutes that I have done over the years and roughly how long they took each way. This is all flat commutes and include city traffic.
7.5 mile (Zero MUPS) - 30 minutes
11.5 miltes (5 miles MUPS) - 45 minutes
16 miles (6 miles MUPS) - 1 hour