Get some hose that has an ID about that of the oil cooler line OD, put that and some heavy plastic tape and various sizes of hose clamps in your tool kit for the trip. That might hold a small leak if applied right, you slit the short section of hose along the side and apply it over a rupture, after taping it first, and clamp it well.

You were planning to take some tools weren't you? At least take a dozen latex gloves. I always carry a few tools and the gloves on long trips, just in case I have a problem as well as to be able to help another Mercedes driver when I find one on the road (not often I might add).
I blew a heater hose while doing 70+ MPH, I smelled the coolant and saw the steam issuing from under the hood as I quickly pulled off the highway and coasted into a gas station which luckily was close by. I am certain if my wife had been driving that engine would have been toast. The temp gauge was crawling higher as I shut the engine off. I used some hose I purchased at an auto parts place a few miles down the road and made a patch until I could get home I drove back (slowly) with the rad cap loose to avoid building up pressure.

Dieseldiehard
1971 220 (gas) 4-spd manual 104041
1979 300TD w/ ’85 turbo engine 288975
1983 300D 237300
1985 300TD 205437