You need to figure on it taking 90 mins from gate to resort. Yes, it can be less (and usually is) but safer to over judge. Then, get checked in at the resort...about 20 mins. Then get on a bus to MK..that could be an hour. So, you could feasibly make your BoG ADR...barely.
You don't say what resort you are staying at. There are ways around the whole issue...but I'm not sure I would recommend them. You could take the chance of tagging your bags and letting DME handle them, while you take a car service to the CR and then walk over to the MK. But, there could be baggage issues when doing that!!
Or, you could take DME to the resort, and then get checked in and then get a cab to the CR..walking over to MK (takes under 10 mins).
Here's my biggest issue....the one and only time I ever booked something important on my arrival day, I missed it!! There was a mechanical issue with our plane in Boston...so we had to get off the plane and wait for another one to be brought in!! I was taking off at the precise time I was 'supposed' to be landing in Orlando!! I thought I had plenty of time to make my activity...missed it by 45 mins!! I seldom recommend booking anything for the first 4 or so hours after planned arrival....it's just a nasty way to start your vacation..worrying and stressing over the time everything is taking!!!