Hetch Hetchy Loop You'll be find the south side to Pate Valley and on the north side to Rancheria Mountain mostly clear most years. Rancheria Mountain is usually snow bound in May, as is Pleasant Valley. In a normal year it's clear by June. In a light snow year, it's clear by May.
The way it's looking so far, it's a light snow year, but a lot could happen in February.
Look at the Glacier Point webcam at
www.yosemite.org/vryos/
It's snowbound through May usually, but clears usually by early June or late May.
Stoves I don't know of any places that rent stoves. REI is in Fresno. There's a mountaineering shop in Curry Village in Yosemite Valley. I would just use one of of those pocket isobutane stoves that uses disposable cartridges (e.g., I have a Giga Power stove). It's the fuel container that worries airport officials, even if empty.