Gear ratio for traveling

Hi everyone! This year, for a summer trip, my wife and I drove with our three daughters from Poland to Tønsberg, Norway for a few days and then to a camping spot in Öland, Sweden. Because of the limited space in a car, I borrowed a Brompton from my friend. I’m not yet familiar with the model range, I think it’s a bit older model with a 3-gear Sram hub. The saddle is not a perfect fit for me, the seat tube is too short for me and grips are not really as comfortable as I would like to. All of these cause a bit of a pain in my buttocks and lower back, as well as wrists (the seat tube being too short come as a surprise, because I had a chance to test ride a Brompton and even though it was only a couple of minutes of riding, I never noticed any problem with saddle being too low, maybe the seat tube was changed between the model I borrowed and current lineup). Nevertheless I fall in love with Brompton even more with every day of riding. At this moment I’m considering buying a 6-speed Brompton with dynamo hub (C Line Explore M6R?) as a commuter and summer trip / traveling bike. Is anyone here able to tell me what are the gear ratios of the three gears on the bike I borrowed, and compare it to the current 6-speed model? I think 3 gears are enough for city riding, but when traveling, every uphill road is a struggle on the 3-speed model, and even the lowest gear is not low enough for me. I’m not expecting the 6-speed model to be a hill climber but it I had 1 (or maybe even 2) gear that is lower than gear “1” in the 3-speed model, it would be enough for me to consider it as my next bike. If you have any tips on choosing the best Brompton for traveling, feel free to share!