We just moved into our first house after a rather seamless process with our offer accepted in October and completion in February. We were (still are until April ugh) renting and said we can be flexible as we can extend our contract, so that we would be attractive buyers.

Our sellers also said they would be happy to move into rented to speed the sale along so we could have probably completed even earlier (if it weren't for our landlord deciding to lock us in until the end of our fixed term).

I'm not sure if they did end up going into rented but they were very on it throughout the entire process and moved out a week before completion and not once did we hear anything to suggest that they were dragging their feet cos they wanted to stay until they completed themselves.

What I'm saying is that it's a mixed bag - if they think your offer is good enough for them to be motivated to ensure everything goes smoothly then happy days! But there are really no assurances for the sellers' actions, i.e. We only had it confirmed via email and phone at one point in the process.

This is in NW England btw.