Use pre soak at car washes let it sit for a few minutes rinse off...

That long of a drive you'll want a pit stop here and there so why not a quick wash.

If you want a good product you can find locally. Stoner's Tarminator is a solid choice.

Try to rinse off the bugs with water initially, if it doesn't work use Tarminator and let it sit for a few minutes followed by a rinse then normal wash. Should break down the bugs enough to rinse right off or soften them enough to wash off cleanly.

I'm moving down to Texas in May, probably the 10th. Leaving Virginia so it will be a long trip. Might get my car cleaned and waxed and head out.