How to scout locations?
Secure accommodation for scouting purposes to avoid rushing into a location without first trialing the location.
After doing your preliminary research, the best way to get a feel for a location is to stay there for a length of time. You can try the following variety of methods to find a short-to-medium term rental.
Apply to listings on websites / apps:
AirBnB, or VRBO: when searching places note any monthly stay discounts but still write to the AirBnB host regardless as they may still offer a reduced rate. Note that in some locations, stays over 30 days are prohibited for such tourist accommodation.
Booking.com: more expensive, but if it is off-season and you are able to speak with them, discounted stays are possible.
Real estate websites: eg. Italy: Idealista.it, immobiliare.it, housinganywhere.com, spotahome.com (for larger cities). Check listings that mention fixed periods (eg. January to May); scroll first to the more expensive listings. Note, Housinganywhere has its own contract setup with extra costs.
Homeexchange is another option but you need to also do an exchange or have built up points.
For larger cities, google "short term rentals Rome" (for example)
Alternatively: Network to reach home owners:
On social media platforms, like Facebook expat groups: submit a post and advertise what you want. Also search the group for current offerings by home owners. Often expats who own a home there are not there all year round but would welcome a reliable tenant (for anti-squat and burglary-deterrent reasons also)
Contact Real estate agents in the location, particularly those who are expats or English-speakers as they are probably connected to expat home owners to whom they have sold a house. They might also have other suggestions.
Highly recommend: Always make a plan for a backup if there are last minute changes.
Other tips:
Off-season is always much easier to get any type of accommodation, particularly medium-term rentals.
Ensure you get security with a type of temporary rental contract (eg. Italy - "transitorio" contract or "Contratto per Finalita' Turistica").
Take precautions against being scammed.
Fortunately, finding a medium-term rental as an expat is easier than finding a long-term rental as an expat. In tourist destinations long-term rental accommodation is typically difficult to find for all, both expats and locals, due to the accommodation pressures arisen from the tourism eg. AirBnB's. Unfortunately, expats are seen to not stay a long time compared to locals, but finding one is not impossible though! (In Italy it is legal for a rental contract to be terminated early by a tenant if the notice period is abided by!)

