A laptop and wifi will be your best friend with this issue. I'd start by staying at RV parks with a tennis court. You might luck into finding someone to play in the spot over. When staying in places that are primarily a vacation spot, I've had good luck calling pay tennis facilities and asking to be matched with a player at my level. City facilities might have a match service. Otherwise, check meetup.com to see if the city has a meetup group of tennis players. Larger cities may have tennis groups with web sites. Craigslist is another option; however, I'd be wary of getting nothing but spam and would probably use the site as a last choice.