Ex-EU connecting at LHR with luggage

I'm trying to plan up a ex-EU trip soon, and the flights i'm finding back into LHR (where i fly to/from with VS with) is cheaper with a same-day connection onto EU. Changing the final airport makes the price bump up a lot.

Whats the maximum time LHR can hold luggage for?

(I intend to ask for a short-check so i can use VS revivals and change, so theres about a 7 hour gap!)

I've actually for an 11 hour gap not 7, but i wanted to check to LHR.

What i'm asking is... whats the maximum time between connecting flights (if not overnight) where they have to check your baggage to heathrow and not your final destination?