Would it be possible in the future with a Sanhedrin to move Sukkot to a different time, say perhaps during Pessah where we can have both a Sukkah and eat Massa in the sukkah and celebrate the going out of Egypt both with a Sukkah, Lulav and etrog (4 species) AND Massa.
I don't believe so.... The Torah tells us when Sukkot falls out, it always is in the fall season...
In telling us about the festival of Sukkot, the Torah says in Parshat Emor, "But on the 15th day of the seventh month (Tishrei), when you gather the crop of the land, you shall celebrate Hashem's festival for seven days" (Leviticus 23:39).
Rashi, the fundamental commentator on the Torah, points out that the holiday of Sukkot must always fall out in the fall season, when the time of harvest comes. This requirement creates significant ramifications on the Jewish calendar. The Talmud (Tractate Sanhedrin 13a) lists several reasons for which the Great Sanhedrin (high court) of 71 judges would periodically add an extra month to the calendar and thereby transform any given twelve-month year into a thirteen-month leap year. One of these reasons was to ensure that the holiday of Sukkot would fall out during the harvest season! This necessity clearly demonstrates how crucial it is for Sukkot to be celebrated in the harvest season, since making the year into a leap year will consequently effect the rest of the calendar as well.
It is logical to assume that Hashem expects us to be harvesting during this time of year. However, a few verses earlier, the Torah commands, "On the first day [of the festival of Sukkot] is a holy convocation, you shall not do any m'lechet avodah (work of labor). . .on the eighth day there shall be a holy convocation for you. . .you shall not do any m'lechet avodah" (ibid. 23:36). Rashi explains that the Torah uses the repetitive language of "m'lechet avodah - work of labor" to tell us that even when it is difficult for us not to work - when we will suffer financial loss by not working - we are still commanded to refrain from working on those days of the festival.
This is extremely puzzling. How does Hashem expect us not to work on Rosh Hashanah, Yom Kippur, and Sukkot - at the climax of the harvest season, the most financially opportune time of the year? How can we properly focus on the High Holidays and the joy of Sukkot when our minds are on profit?
The answer to this is a crucial message that we must absorb during this time of year. The Torah tells us that the reason we dwell in the sukkah is to remember how Hashem made sukkot for the Children of Israel to live in during their forty years of travel in the desert. Hashem also provided for all of our material needs, including providing us miraculous food in the form of the manna. Moses was instructed to place a vial of the manna in the Mishkan (Tabernacle) so that in the future we would always remember how well Hashem took care of us in the desert (Exodus 16:32). In fact, before the destruction of the first Temple, Jeremiah reprimanded the people for not devoting themselves to the study of the Torah according to their abilities. They responded that they needed to earn a living. Jeremiah then pulled out the vial of manna and told them that in the desert, the Jews learned Torah day and night. All their desires and needs were met by Hashem; they had no need to work. If the Jews would again learn, said Jeremiah, Hashem would provide them with whatever they might want.
This message is just as true today as it was in Jeremiah's time. We know that on Rosh Hashanah, Hashem judges all aspects of our lives for the coming year. This includes our parnasah, our income. We will make a certain fixed amount of money this year no matter how long we spend at work. Hashem has many agents in His world to give or take money away from us. If so, why must we work at all? Why can't we learn Torah all day and manna will fall from heaven for us?
Rabbi Moshe Chaim Luzzatto, the great 18th century Torah scholar and philosopher, provides us with an answer in his classic work Mesillat Yesharim. The reason dates back all the way to the Garden of Eden. When Hashem cursed Adam that he must work the ground to sustain himself, the curse was not only applicable for one generation. This curse extends to Man for all time, requiring him to always do some work in order to make a living. Man cannot sit back and learn all day without doing any work. Some form of exertion must be made to earn a living. Once that effort is made, however, Hashem will provide us with all the money we are destined to have.
Going into Rosh Hashanah with such an awareness that all of our sustenance comes from Hashem and remains constant no matter how much work we invest, makes it quite easy to refrain from working on the High Holidays. These are days that Hashem doesn't want us to work, and He will sustain us on these days without our work. If, however, we have not realized this during Rosh Hashanah and Yom Kippur, Hashem gives us another chance to internalize this message on Sukkot. By refraining from work and dwelling in our sukkah, we ingrain within ourselves the concept that this entire world is like our fragile sukkah. We only live by the kindness of Hashem, even while we dwell in our "sturdy" homes. To earn the livelihood Hashem gives to us, we must only put forth a bit of effort when Hashem wants us to. Then we will realize that our income really is "20th century manna from Heaven", and spend our time learning the precious Torah Hashem gave to us.