We ended up selling with no onward purchase due to relocating and had to live with family for a year.
Check rental availability and any conditions on renting by ringing agents now. Short term rentals were impossible as high competition meant landlords only wanted long term tenants. We tried negotiating a long term let on a holiday cottage over winter, but it was expensive as they were furnished so we would have had rental and storage costs, and there was no security of tenure so with young children we felt it was too high risk.
Consider that you will incur double moving costs and possibly storage costs, for example if you end up renting something smaller or without a garden you may need to store outdoor things or some furniture. Our family member had little room for our possessions in their home so apart from toys and clothes most of our things went into storage. We used the same company for removals and storage but didn't have instant access to our possessions as long term storage arrangements meant our stuff was stacked high in big shipping containers.
Beware how unsettling it can be not to have a permanent home and uncertainty on when you will move. I found it really stressful as did our children, and it made settling into our new area more challenging than it would have otherwise been.
It took ages to find somewhere to buy. One purchase fell through after 4 months as the vendors couldn't find anything to buy and took their house off the market. Then there was nothing suitable for us to buy for months. I was reading threads on here from posters who had got stuck renting for years!
Consider that time out of the property market means you don't have an appreciating asset and are not paying down your mortgage during that time. We had to keep our sale equity in safe savings accounts at a time of high inflation so it wasn't a great financial move.
It did put us in a great proceedable position for buying and we were relentless with local estate agents, some of whom let us do early viewings on properties before they went to market as they knew we were serious buyers, but I wish we had been a bit less hung ho and wouldn't sell without somewhere to move into again.