Yes, as Princess says, it's different for everyone, and it depends how they start you off.
My friend went up to deliver just before me. She was induced too - though I can't think how just now - her labour was 16 hours and she was knackered, it was very hard work.
I went into the room next door just as tea and toast was being ordered for her and started mentally adding 16 hours to work out when I might be done.
They hooked me up to the drip, I had a wee snooze while fluids were fed in and the midwife did her paperwork, then I called DH to drive in (it was about 5 or 6am!). Once DH arrived, they started the oxytocin and for me it took immediate effect. It was a fast and furious, but quite mobile delivery. I used a ball, then leaned over the bed, then on my knees leaning over the bed head, then sort of sitting to deliver. Took about 3 hours altogether. I didn't have an epidural but I did use a lot of gas and air, though not while pushing. It was very intense, but mercifully short.
I had wanted to delver on the midwife-led unit downstairs so I was a bit anxious when that went out the window. As it was, the midwives did their best to allow me to be mobile, to change position (the delivery suite bed was like a transformer and finished up in a birthing chair shape) and no doctors would be involved unless it was necessary. The anaesthetist put the cannula in as the midwife was struggling, and a sonographer scanned me to check DD's position - no one could tell which way up she was from feeling - her bottom was doing a good head impression under my ribs! Induction needn't mean you flat on your back, closely tied to the drip so perhaps talk to your midwife about how you can make the best of this new situation.
Speed-wise, turned out it could just be how I give birth. DS, 2 years later, was spontaneous (also a bit 'early', though not prem) and labour ramped up very quickly to delivery in under 4 hours, start to finish. He was back to back or it would have been much quicker. I had him in water, with just gas and air.
I think I have quite a high pain threshold, I didn't realise this at the time but I think it's fairly unusual to go straight to drip without being offered and taking an epidural.
It's hard when your birth plan changes for reasons beyond your control but I decided to go with the flow and concentrate on getting DD out however the midwives suggested! Doesn't bother me now that she wasn't a relaxing, whale song type delivery - she's here and safe, that's all that matters.
Very best of luck for Saturday! Let us know how you get on.