How many local bike shops can you actually test ride a bike, ie give it a good off road hammering, rather than a pootle round the car park for 5 min to try it for size?
A lot depends on whether the bike belongs to the shop or the distributor. For most high-end brands you should be able to get something for a day, if not the weekend.
Regarding buying blind though, you’ve to watch out for more than just size, especially if buying a full-sus. Depending on what you’ve been used to riding before, the feeling of the suspension can be a lot different. Things like that can mostly be sorted out with a shock tune, but it all adds cost.