...How fast is an Archer anyhow? Small craft in onscreen Trek haven't been particularly speedy: shuttles haven't clocked anything above warp four, and it was once a plot point that a runabout couldn't top warp five. Yet the Vanguard adventures weren't limited to runabout-like swift transit from star to star, but actually involved or implied a few chases against big ships as well.
Fast. The writers' bible says warp 9.4 on the TNG scale, which is warp 12 and change on the TOS scale, or about 1800c. That's "top cruising speed," so one can make almost five lightyears a day. Not bad.
So there might not actually be that much travel-related downtime. On the other hand, depending how long the average survey takes, that could mean a better work/life balance, something like what was shown at the beginning of "Long Shot." A couple days of travel, where the operational crew is busy and the science crew can relax, then a couple days landed putting bugs in jars, where the scientists can keep busy and the other half can take some time off, and then it's back to space and on to the next planet. They could also go slower to conserve fuel and stretch the time between surveys for all sorts of reasons.
In either case, I think the better comparison might be a submarine crew than a ground patrol. Subs go out for three to six months at a time, and might only have a couple of port stops during that time. Granted, submarines have crews ten times as large as the
Sagittarius, but I'm going to guess it's more spacious looked at on a per-person basis. In either case, the crew of the
Sagittarius seem to have a lot more opportunities to stretch their legs during their regular duties.
While I was googling for this post, I found
this page on the NR-1 research sub which does seem comparable to an Archer-class ship. It's got a ten-to-fifteen person crew and could stay out for as long as a month (theoretically, though two weeks seems more reasonable), had a fraction of the space of the ship we're talking about, and had no crew facilities to speak of.
I can't remember if it was "Long Shot" or the writers' guide or what, but somewhere it was mentioned that you only got on an Archer-class ship if the lifestyle appealed to you and you volunteered. With only about a dozen of them in the fleet (at least, based on the list of names in the writers' notes), that's only a hundred and seventy or so people out of all the Starfleet. You couldn't half-fill one Constitution-class with every misfit and weirdo who wanted the challenge of living on an Archer.