A foreigner who has departed before the expiry of the period specified in the visa issued in a visa year shall not be allowed to use the visa by adding the remaining period to another visa year. If any foreigner who has entered Nepal towards the end of a visa year desires to extend his/her stay into the new visa year, he/she may do so by purchasing another visa for the New Year. Provided, however, that the computation of the fees for such period shall be made on the basis of the total period of the stay.
Things can happen when you're travelling that are out of your control, so insurance comes in handy. Considering the unpredictable nature, remote destinations and conditions encountered it is required to have travel medical insurance, including Acute Mountain Sickness coverage, and evacuation to the in case of emergency. You're going to spend your hard-earned money to enjoy your holiday-why not spend a bit more to safeguard it?
Parts of your trip go above 2800 metres / 9200 feet where it is common for travelers to experience some adverse health effects due to the altitude - regardless of your age, gender and fitness. It even happened to Sir Edmund Hillary!
Most places have facility during your trek to re-charge electronic devices by local hydro power and solar energy upon small fee which is fair if you compare remoteness. The common Europium Union etc. (not UK ) two round pin plugs model work in Kathmandu and trekking, but with a wobbly fit, Nepalese and Indian outlets are just over a mm wider . If you have a Apple USB charger, the " big" model , you can swap the duckhead - or use a standard cable that ends with same two round prongs. You can buy cheap adapters in Kathmandu, perfect size at the super store next to Mountain Mart Trek sales office.
Technology also has been touched to Himalayas which made the world smaller. You can be in contact with families and friends while you are in trekking connecting Wi-Fi with small cost. About 60% of your trekking route has Wi-Fi coverage.
Most bathrooms are shared and toilets can be either squat type or the western version. Most of the Tea Houses have running water facility. Many of them have hot water available for bathing at additional cost. Solar heaters depend on day's weather. But we discourage our groups from using water heated by wood, as lack of firewood in most villages is a big environmental concern in Nepal. It is advisable to carry wet wipes as an alternative.