Not a coach, but I like hypotheticals.
I'm assuming they're all in track right now, and all running about that 40 mpw. So I would start things now. They want to do anything to win state in XC? Cool, we're training through track season. Sure, we'll race hard and get after it, but I am not going to focus their workouts on running the best 1 and 2 mile races possible. We're going to build things up aerobically all in prep for summer and then launching into fall.
For March and April we would take our time getting up to 55ish mpw. Depending on how many track meets we have, we might be doing 0 to 1 workout a week. We would do strides multiple times a week, however.
In May we're finishing up track, taking maybe a week or 10 days off to very, light, then diving back into the mileage. By June I want us running in the 60s, and in the end of summer we're going to be in the 70s (on 6 days a week, everyone gets a day off, and yes, that is required). Doubling occasionally might be OK, but we'll have to feel it out for the individuals.
We're not doing anything fancy in the summer. Long runs bump up to an 1:45, sometimes there is some slight progression and faster finishing there, but we're usually just getting the time in. We mix in the occasional fartlek workouts, hills, and some tempos (very careful control here, I'd rather have them running too slow rather than too fast).
In the early season the miles will stay around high 60s and 70s. I've got 7 guys, and we practice or meet 6 days a week. I will meet individually with each runner once a week. So a couple days a week I talk to two. We check in on everything. Any pains, sleep issues, recovery, dating, homework, whatever, we talk about it. We adjust workouts/miles accordingly. We want as few setbacks as possible.
In the early season we start racing, but we're practicing these races and testing our new fitness, we're not necessarily trying to win every meet. The guys are around the same ability, so what happens when they run as a serious pack? What happens when two of them jump out and try to hang with another school's front runner? Sometimes we just run these races as tempo type workouts. We're looking to see when the team runs best and when each individual runs best. Hopefully we can dial that in by State (early November?).
In the last month or so of the season we scale back some on the miles though not a lot (maybe back to 50s, gotta see how everyone feels first). We also do a more classic style 5k workouts in this period (800s, 1000s, miles, etc.) to sharpen things up and give them some confidence in seeing how fast they can actually go. They should be starting to fly at this time. In fact, we might have had to rein things in come September if everyone has been consistently buying in.
However, I don't know if winning state after getting last is possible. Maybe. But top 10, or top 5 seems like a huge and potentially doable goal. Guess it depends on the other schools, too.
TLDR, more miles, base workload on feel, do fewer workouts rather than too many, very short and late specific workout period