When I had my M33 Chariot, I used it for work miles. Bought as a non-runner that wouldn't even kick over, with a stuck clutch, its first shakedown run after a local MOT was 120 miles.
Daily 60 mile roundtrips, including major A6/A45 interchange for about 4/5 months.
Then regular 160 miles each way to Llandod + local stuff while there for a few days each time.
150+ miles each way to Cheshire.
65 miles each way to Boston on many occasions.
Plus trips to club meetings etc etc.
Cruising speed 50/55 mph with rare bursts of 60mph.
No problem with traffic, when necessary could match lorries doing 56mph.
Your trip is, what, 40 miles each way, so with stops, a very nice day out? Just go for it.