I have rented a portable scooter from Buena Vista on trips a few years back - probably the same or similar to what Gold rents. BV told me that the heavier a person is, the less the battery will last. I think they said it was not as recommended for those over 200lbs. I suggest asking Gold what to expect from the battery life and performance for your situation just to see what they say. I was under 200lbs and found the portable rentals I got from Buena Vista were "ok" but not great in terms in battery life. I often had to recharge them once during the day. Generally not an issue with speed except going up the bus ramps now that I think about it. I don't know if the current portable rental models could have the same issues but it could be worth asking about.
gold rents the gogo sport, the big difference is they replace thier entire fleet every 6onths where Buena Vista doesn't, so the battery is generally going to be in better condition. Additionally Gold only uses the extended battery.
As for the Victory 10, if you can fold down the back row, it should fit in most SUVs, but if you need the back row it.would be a challenge. Although, I do believe thier victory 10 does break down.
We fit two of them in the back of a Dodge Caravan with the back row folded down.
If you are using your own vehicle (or renting a similar sized vehicle), most of your local medical supply supply stores should have Victory 10s in stock and I have found they are usually happy to help you see if you can get it to fit. Just keep in mind that Gold has the captains chair, so that is a factor.
What we did was lower the tiller, then fold down the seat. We then put it in neutral, lifted the front over the lip and then lifted the back up, pushed in. Then take it out of neutral (this is key) and reverse the process to get it out. It sounds harder than it is.
And under your circumstances, I would definitely try for the Victory 10 if you can figure out how to make it fit. It would be more comfortable and the batteries would last.longer during the day.
But the gogo sport will work, just watch the battery and possibly try to plugin when you go to eat, etc.
You might also be able to ask them to bring both and you can try the victory 10 in your vehicle and if it indeed can't fit, you can stick with the gogo sport.
But ultimately they generally know what can and can't work, I just think your circumstances would make the victory 10 a better choice.