Yes, these days, the guesthouses, lodges, teahouses and restaurants offer the facility of Wifi to the trekkers along the trail where they stay. From Lukla to Gorekhshep, all along the trail, you can enjoy the facility of Wifi but they charge you some money like Rs.200-500 per device. Alternatively, you can buy data pack from Kathmandu with local SIM card. This will help you a lot throughout the trip.