Try Booking.com to search for places to stay in your locations. You can limit the number of people to 1 by choosing 1 adult, 0 children in the "Guests" box on the upper left of the screen.
You can use the "advanced" search options there, too, but I prefer to get the initial results, then refine them using the options categories down the left side of the screen. I ignore the stars, but require that the review score be 8+. I sort the results by review score and I just noticed you can pick "solo travellers" from that drop down box.
You will need to do this for yourself. This is a little search I did as an example for you. One person, leisure travel, 1 night 16 October, breakfast included, review score 8+ and switched to 50-100EUR for the price. They are sorted by review score by solo travellers. All kinds of lodging options came up in the 57 results. For your own search, you could refine those, too.
Please note that I have never booked through Booking.com. I have only used it to identify possible lodgings, then contacted them directly to book. The place itself will likely have more availability than the rooms they give to booking agencies to sell.