My own address is 5 digits, and I live in the middle of Seattle.
When I lived in Houston I wanted my neighbour’s house. Their number was 12345, I was 12347.
What a coincidence! I have that same combination on my luggage!
That can’t be it, because then they wouldn’t be a liar if they was to say to you they couldn’t get much higher.
As a Brit I find these “mile-based” or “cross-street-based” numbering systems to be cheating 
The highest street address in the UK, where we just number houses consecutively along the road regardless of placement (albeit usually odd on one side, even on the other), is apparently 2679 Stratford Road, Hockley Heath, near Birmingham.
You’ll note that none of these high numbered streets is in the northeastern U.S. Few of the older colonial era or early 19th century cities were developed on a grid plan, although New York is a famous exception. (Philadelphia and Washington, DC also use grids but the early cities were tiny.) Even when a grid was used in the city, suburban developments came decades later and didn’t extend the grid in any standard fashion.
Most house numbers in New England or upstate new York grow by propinquity rather than block just as in England and so remain low for many miles. There is not a single 5 digit house number in Monroe County, home to Rochester, NY, even though it’s about 35 miles wide and moves well into farm country.
The use of street numbers well into the suburbs is mostly unheard of anywhere in the old U.S. Seattle has suburban streets that go continually into the 350s or so. Two different conventions.
1 Armstrong-Aldrin Place, Tranquility Base, Luna
There are some house numbers in the 600,000s in rural Ontario about three hours northwest of Toronto. Unfortunately I can’t remember the exact street they’re on, but I think it may be Highway 10, which is Hurontario Street in Toronto, signifying that the street runs from Lake Ontario to Lake Huron.
I wonder if, in the U.S., five-digit street numbers are disfavored because they look too much like zip codes?
Cleveland is not as old as East Coast cities, but the numbered streets go up to 367 on the east side and 231 on the west side, across many suburbs. On the East Side, the streets are numbered well into Lake County. The addresses on the cross streets go along with the numbered street number (i.e. 24800 Euclid Avenue is at E. 248th St.)
Cleveland had mostly named streets until 1906, when a Great Numbering was decreed during the Progressive administration of Mayor Tom Johnson. Modernity, efficiency and all that. I wonder how many people pass by the Willson Apartments at E. 55th and Chester not knowing that E. 55th used to be Willson Avenue.
I always enjoyed driving in Salt Lake City because of the extremely logical numbering system. You can get to an address like 1050 E 800 S without a GPS or a sense of direction. It must have been laid out by engineers, not politicians.
Are those map-grid-coordinate-type numbers, or sequential along-the-street numbers?
my address used to be 59497 tonester circle in michigan
You beat me to it, and I just Haight that.
They appear to be sequential, but starting at a high number. Here you can see the position of 632000 Route 10 in Orangeville. The numbers increase going north, but 632000 is the smallest address I’ve been able to find in this sequence. Just a few kilometres south, the route becomes Hurontario Street with addresses in the vicinity of 21300 (which does seem to be “legitimate” according to the OP’s definition).
Of course, that’s assuming the address numbers on Google Maps are accurate.
ETA: Also notice the side streets with addresses in the 200,000 or 300,000.
I went googlemapping and found an address in the 300000’s (Stone Tree Golf and Fitness Club) along Highway 10 just south of Owen Sound. I’m sure that one time at the Map Library in Toronto, someone explained that these were directly derived from map coordinates, but my google-fu seems to be lacking tonight and I can’t find any cites.
I believe that’s actually in a local depression.
The premise is mistaken: There are lots of five-digit street numbers in the U.S.
But considerably fewer than four- or three-digit numbers, IME, especially in residential areas.