The dimensions are pretty much spot on - exactly 18 including the legs, and pretty close to 38 with the standard lid (I can't be as precise on that as mine has the FTSs2 lid on it at the moment which is shallower, so I measured the standard lid separately). Of course you'll need head space for your choice of airlock/blow off above the 38", and the 38" doesn't include the adjustable feet; it's from the bottom of the legs. You may get away with slightly less than 18 in width if you have enough depth and orient it at an angle, but you're probably still looking at 17".
It'll be tight in the dims you list, but I think it'll fit so long as your airlock doesn't poke up too high.
I already had a fridge so when it didn't fit I went with the FTSs2 solution and so far have been very happy with it. I'm only 2 batches in on the new gear, so I can't speak to longevity, but it warms and cools like it should...