Agree take what you have got.
Get a small tool box and use it when fettling the bike (this way you know what you have and that it works) and take it with you.
Mole grips, junior hack saw also useful. Spare brake levers front and back, clutch lever, front brake, pads, spare chain. Front tube, dog turds, Tyre levers.
Keep any usable spare you replace such as grips, tensioner pads, mudguards etc that would do to get you to the finish.
Best plan is you have it you won't need it.
And yes spare handle bars with a grip fixed to clutch end