My House Contents insurance covers the bike against theft, even when abroad. I think that annual cover, including 30 days out of the country is about £22 for £1500 of bikes. It doesn't cover accidental damage. I never even asked about that because I thought it would be ruinously expensive. I could be wrong. The rest of my travel insurance is on a general annual policy that covers the usual stuff...lost baggage, bringing my corpse home etc etc. Getting an annual policy is really worth considering rather than getting a policy for individual weeks abroad, if you are lucky enough to go away more often.
Have a great holiday.