I just returned from Ireland and faced the same challenge. I have a Domke bag exactly like yours, but I found it too small from a X-T2 body and a few lenses. I highly recommend the Billingham Hadley Pro as a good next size up. I picked up a black and tan Hadley and it was perfect for my X-T2 and a few lenses, even my GoPro Fusion 360 camera and the short 360 stick, smaller iPad Pro and pencil for Lightroom work also fits in the notebook sleeve in back of the bag.. Hadley is a bit more pricey but I've had this one for years and it is now my main travel camera bag. I don't regret the investment. Like Domke, the Hadley bags look better as they age.
You will love Ireland, photographically and all the rest. I look forward to returning soon with the same kit.